Genomes and Genes
Summary: A highly neurotoxic polypeptide from the venom of the honey bee (Apis mellifera). It consists of 18 amino acids with two disulfide bridges and causes hyperexcitability resulting in convulsions and respiratory paralysis.
Publications181 found, 100 shown here
- Tuning the excitability of midbrain dopamine neurons by modulating the Ca2+ sensitivity of SK channelsHuifang Ji
Department of Psychiatry, Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD 21228, USA
Eur J Neurosci 29:1883-95. 2009..adaptation and slowed spontaneous firing, effects attributable to an increase in the amplitude and duration of an apamin-sensitive afterhyperpolarization...
- Differential expression of the small-conductance, calcium-activated potassium channel SK3 is critical for pacemaker control in dopaminergic midbrain neuronsJ Wolfart
Medical Research Council, Anatomical Neuropharmacology Unit, Department of Pharmacology, Oxford University, Oxford OX1 3TH, United Kingdom
J Neurosci 21:3443-56. 2001..This provides a cellular framework to understand the functional consequences of altered SK3 expression, a candidate disease mechanism for schizophrenia...
- Development of action potentials and apamin-sensitive after-potentials in mouse vestibular nucleus neuronesM B Dutia
Department of Physiology, Medical School, Edinburgh, UK
Exp Brain Res 118:148-54. 1998..Immature type B cells had somewhat narrower spontaneous spikes that were followed by a delayed, apamin-sensitive AHP...
- Nitric oxide acts as a volume transmitter to modulate electrical properties of spontaneously firing neurons via apamin-sensitive potassium channelsLiana Artinian
Department of Biology, Georgia State University, Atlanta, Georgia 30302 4010, USA
J Neurosci 30:1699-711. 2010..Both effects of NO were mediated by inhibition of Ca-activated iberiotoxin- and apamin-sensitive K channels, but only inhibition of apamin-sensitive K channels fully mimicked all effects of NO on ..
- Evidence for an apamin-sensitive, but not purinergic, component in the nonadrenergic noncholinergic relaxation of the rat gastric fundusDiego Currò
Institute of Pharmacology, School of Medicine, Catholic University of the Sacred Heart, L go F Vito, 1, I 00168 Rome, Italy
Br J Pharmacol 143:785-93. 2004..Pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (100 microM), apamin (0...
- P2Y1 receptors mediate apamin-sensitive and -insensitive inhibitory junction potentials in murine colonic circular smooth muscleYong Zhang
Gastrointestinal Diseases Research Unit, Queen s University, Kingston, Ontario, Canada
J Pharmacol Exp Ther 333:602-11. 2010..In most tissues this neurotransmission is apamin-sensitive, but recent studies in human colonic circular smooth muscle (CSM) suggest the presence of apamin-..
- Differential distribution of three Ca(2+)-activated K(+) channel subunits, SK1, SK2, and SK3, in the adult rat central nervous systemM Stocker
Molekulare Biologie Neuronaler Signale, Max Planck Institut fur experimentelle Medizin, Gottingen, Germany
Mol Cell Neurosci 15:476-93. 2000..Our results reveal the functional role of SK channels with defined subunit compositions in some neurons and open the way to the identification of the molecular determinants of AHP currents in many brain regions...
- Regional differences in distribution and functional expression of small-conductance Ca2+-activated K+ channels in rat brainClaudia A Sailer
Institute for Biochemical Pharmacology, University Innsbruck, A-6020 Innsbruck, Austria
J Neurosci 22:9698-707. 2002..Whole-cell recording showed a sharp segregation of apamin-sensitive SK current within the hippocampal formation, in agreement with the SK2 distribution, suggesting that SK2 ..
- Control of electrical activity in central neurons by modulating the gating of small conductance Ca2+-activated K+ channelsP Pedarzani
, , Germany
J Biol Chem 276:9762-9. 2001....
- Tamapin, a venom peptide from the Indian red scorpion (Mesobuthus tamulus) that targets small conductance Ca2+-activated K+ channels and afterhyperpolarization currents in central neuronsPaola Pedarzani
Department of Physiology, University College London, London WC1E 6BT, United Kingdom
J Biol Chem 277:46101-9. 2002..This toxin distinguished between the SK channels underlying the apamin-sensitive I(AHP) and the Ca(2+)-activated K(+) channels mediating the slow I(AHP) (sI(AHP)) in hippocampal neurons...
- SK channels and NMDA receptors form a Ca2+-mediated feedback loop in dendritic spinesThu Jennifer Ngo-Anh
Vollum Institute, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
Nat Neurosci 8:642-9. 2005..Thus, blocking SK channels facilitates the induction of long-term potentiation by enhancing NMDAR-dependent Ca(2+) signals within dendritic spines...
- Bradykinin-induced, endothelium-dependent responses in porcine coronary arteries: involvement of potassium channel activation and epoxyeicosatrienoic acidsArthur H Weston
Faculty of Life Sciences, University of Manchester, G38 Stopford Building, Manchester M13 9PT
Br J Pharmacol 145:775-84. 2005..of IK(Ca) and SK(Ca) channels using 10 microM TRAM-39 (2-(2-chlorophenyl)-2,2-diphenylacetonitrile) plus 100 nM apamin (leaving an iberiotoxin-sensitive component), whereas the response to substance P was abolished...
- Protease-activated receptors mediate apamin-sensitive relaxation of mouse and guinea pig gastrointestinal smooth muscleT M Cocks
Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
Gastroenterology 116:586-92. 1999..The aim of this study was to determine if PAR-1 and PAR-2 mediate gastrointestinal smooth muscle relaxation and to clarify the underlying mechanisms...
- Inhibition of apamin-sensitive calcium dependent potassium channels facilitate the induction of long-term potentiation in the CA1 region of rat hippocampus in vitroT Behnisch
Leibniz Institute for Neurobiology, Project Group Neuropharmacology, Magdeburg, Germany
Neurosci Lett 253:91-4. 1998Using field potential recording in the CA1-region of rat hippocampal slices we investigated the effect of apamin; a specific antagonist of small conductive calcium activated potassium channels on long-term potentiation (LTP)...
- An intermediate conductance K+ channel in the cell membrane of mouse intestinal smooth muscleF Vogalis
Brockton West Roxbury VA Medical Center and Harvard Medical School, 1400 VFW Parkway, Boston, MA 02132, USA
Biochim Biophys Acta 1371:309-16. 1998..IK channels were blocked by 2-5 mM external TEA and were sensitive to both charybdotoxin (100 nM) and apamin (500 nM)...
- SK3 is an important component of K(+) channels mediating the afterhyperpolarization in cultured rat SCG neuronesR Hosseini
Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
J Physiol 535:323-34. 20011. Our aim was to identify the small-conductance Ca(2+)-activated K(+) channel(s) (SK) underlying the apamin-sensitive afterhyperpolarization (AHP) in rat superior cervical ganglion (SCG) neurones. 2...
- The noradrenergic inhibition of an apamin-sensitive, small-conductance Ca2+-activated K+ channel in hypothalamic gamma-aminobutyric acid neurons: pharmacology, estrogen sensitivity, and relevance to the control of the reproductive axisE J Wagner
Department of Physiology and Pharmacology, Oregon Health Sciences University, Portland, Oregon 97201, USA
J Pharmacol Exp Ther 299:21-30. 2001..The corresponding I(AHP) was sensitive to antagonism by CdCl2 (200 microM), apamin (0.3-1 microM), and dequalinium (3 microM)...
- Small conductance Ca2+-activated K+ channels formed by the expression of rat SK1 and SK2 genes in HEK 293 cellsDavid C H Benton
Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
J Physiol 553:13-9. 2003..Co-expression of rSK1 with rSK2 also changed the channel pharmacology. The sensitivity of SK current to block by apamin was reduced approximately 16-fold from an IC50 of 94 pM (for SK2 alone) to 1.4 nM (for SK2 and SK1 together)...
- Chemical synthesis and structure-activity relationships of Ts kappa, a novel scorpion toxin acting on apamin-sensitive SK channelC Lecomte
Biochemistry Laboratory, CNRS UMR 6560, Faculty of Medicine North, Marseille, France
J Pept Res 54:369-76. 1999..kappa, was indistinguishable from the natural toxin when tested in vitro in competition assay with radiolabelled apamin for binding to rat brain synaptosomes (IC50 = 3 nM)...
- An apamin- and scyllatoxin-insensitive isoform of the human SK3 channelOliver H Wittekindt
Department of Applied Physiology, University of Ulm, Ulm, Germany
Mol Pharmacol 65:788-801. 2004..The most obvious distinguishing feature of this new isoform was that whereas hSK3 was blocked by apamin (Kd=0.8 nM), scyllatoxin (Kd=2.1 nM), and d-tubocurarine (Kd=33...
- Small conductance Ca2+-activated K+ channels as targets of CNS drug developmentThomas Blank
Department of Molecular Neuroendocrinology, Max Planck Institute for Experimental Medicine, D 37075 Goettingen, Germany
Curr Drug Targets CNS Neurol Disord 3:161-7. 2004..Peptide toxins such as apamin and scyllatoxin, as well as organic compounds such as quaternary salts of bicuculline, dequalinium, UCL 1684 and ..
- Fast, but not slow, effects of olivocochlear activation are resistant to apaminN Yoshida
Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114, USA
J Neurophysiol 85:84-8. 2001..We measured in vivo effects of apamin, a blocker of small-conductance (SK) K(Ca) channels, and charybdotoxin, a blocker of large-conductance K(Ca) ..
- Cholinergic synaptic inhibition of inner hair cells in the neonatal mammalian cochleaE Glowatzki
The Center for Hearing Sciences, Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
Science 288:2366-8. 2000..The synaptic currents, as well as the inner hair cell's response to acetylcholine, are mediated by a nicotinic (alpha9-containing) receptor and result in the activation of small-conductance calcium-dependent potassium channels...
- A transiently expressed SK current sustains and modulates action potential activity in immature mouse inner hair cellsWalter Marcotti
School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
J Physiol 560:691-708. 2004..3 Ca(2+) channels in its activation. On the basis of its high sensitivity to apamin (K(D) 360 pM) it was identified as a small-conductance Ca(2+)-activated K(+) current (SK), probably SK2...
- Ca(2+)-activated K+ channels: molecular determinants and function of the SK familyMartin Stocker
Wellcome Laboratory for Molecular Pharmacology, Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
Nat Rev Neurosci 5:758-70. 2004....
- Apamin interacts with all subtypes of cloned small-conductance Ca2+-activated K+ channelsM Grunnet
Department of Medical Physiology, The Panum Institute, University of Copenhagen, Denmark
Pflugers Arch 441:544-50. 2001The purpose of the present study was to examine how apamin interacts with the three cloned subtypes of small-conductance Ca2+-activated K+ channels (hSK1, rSK2 and rSK3)...
- Domain analysis of the calcium-activated potassium channel SK1 from rat brain. Functional expression and toxin sensitivityDieter D'Hoedt
Wellcome Laboratory for Molecular Pharmacology, Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, U K
J Biol Chem 279:12088-92. 2004..In heterologous expression systems, SK2 and SK3 currents are blocked by the bee venom toxin apamin, just as well as the corresponding neuronal AHP currents...
- Apamin-sensitive, small-conductance, calcium-activated potassium channels mediate cholinergic inhibition of chick auditory hair cellsW A Yuhas
Department of Cell and Structural Biology, University of Colorado Health Sciences Center, Denver 80262, USA
J Comp Physiol A 185:455-62. 1999..The peptides apamin and charybdotoxin were used to distinguish the calcium-activated potassium channels involved in the acetylcholine ..
- Effects of intracellular stores and extracellular Ca(2+) on Ca(2+)-activated K(+) currents in mature mouse inner hair cellsWalter Marcotti
School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
J Physiol 557:613-33. 2004..This current was still present during superfusion of either IbTx (60 nm) or apamin (300 nm) but was abolished in Cs(+)-based intracellular solution or during superfusion of 5 mm TEA, suggesting the ..
- Characterization of an apamin-sensitive potassium current in suprachiasmatic nucleus neuronsK Teshima
Center for Research on Occupational and Environmental Toxicology, L606, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, OR 97239-3098, USA
Neuroscience 120:65-73. 2003..However, antagonists of small conductance Ca(2+)-activated K+ channels, apamin and d-tubocurarine, reduced the amplitude of the membrane afterhyperpolarization and inhibited the spike frequency ..
- Characterization of an apamin-sensitive small-conductance Ca(2+)-activated K(+) channel in porcine coronary artery endothelium: relevance to EDHFM P Burnham
School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK
Br J Pharmacol 135:1133-43. 20021. The apamin-sensitive small-conductance Ca(2+)-activated K(+) channel (SK(Ca)) was characterized in porcine coronary arteries. 2...
- An amino acid outside the pore region influences apamin sensitivity in small conductance Ca2+-activated K+ channelsAndreas Nolting
Laboratory of Molecular Pharmacology, Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, United Kingdom
J Biol Chem 282:3478-86. 2007..The bee venom toxin apamin inhibits exclusively the three cloned SK channel subtypes (SK1, SK2, and SK3) with different affinity, highest for ..
- Apamin inhibits NO-induced relaxation of the spontaneous contractile activity of the myometrium from non-pregnant womenBeata Modzelewska
Department of Biophysics, Medical University of Bialystok, ul, Mickiewicza 2A, 15 089 Bialystok, Poland
Reprod Biol Endocrinol 1:8. 2003..In order to assess whether apamin-sensitive K+ channels play a role in NO - induced relaxation of the human uterus, we have studied the effect of ..
- Maurotoxin: a potent inhibitor of intermediate conductance Ca2+-activated potassium channelsN A Castle
Icagen Inc, Durham, North Carolina 27703, USA
Mol Pharmacol 63:409-18. 2003..Maurotoxin did inhibit (86)Rb efflux (IC(50), 45 nM) through, and (125)I-apamin binding (K(i), 10 nM) to SK channels in low ionic strength buffers (i.e...
- K+ channels and the microglial respiratory burstR Khanna
Division of Cellular and Molecular Biology, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
Am J Physiol Cell Physiol 280:C796-806. 2001..The respiratory burst was markedly inhibited by blockers of SK2 (apamin) and SK4 channels (clotrimazole and charybdotoxin), and to a lesser extent, by the potent Kv1.3 blocker agitoxin-2.
- Partial apamin sensitivity of human small conductance Ca2+-activated K+ channels stably expressed in Chinese hamster ovary cellsT J Dale
Ion Channel Biology Group, Systems Research, GlaxoSmithKline Research and Development, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK
Naunyn Schmiedebergs Arch Pharmacol 366:470-7. 2002The bee venom toxin apamin is an important drug tool for characterising small conductance Ca(2+)-activated K(+) channels (SK channels)...
- Evidence for involvement of both IKCa and SKCa channels in hyperpolarizing responses of the rat middle cerebral arteryAlister J McNeish
Department of Pharmacy and Pharmacology, University of Bath, Bath, UK
Stroke 37:1277-82. 2006..The relaxation was unaffected by specific inhibitors of IKCa (TRAM-34, 1 micromol/L) or SKCa (apamin, 50 nmol/L) alone or in combination...
- Small-conductance, calcium-activated potassium channels from mammalian brainM Kohler
Vollum Institute, L 474, Oregon Health Sciences University, 3181 Southwest Sam Jackson Road, Portland, OR 97201, USA J Maylie, Department of Obstetrics and Gyne
Science 273:1709-14. 1996..The channels that formed from the various subunits displayed differential sensitivity to apamin and tubocurare...
- Bicuculline methiodide potentiates NMDA-dependent burst firing in rat dopamine neurons by blocking apamin-sensitive Ca2+-activated K+ currentsS W Johnson
Department of Physiology and Pharmacology, Oregon Health Sciences University, Portland 97201, USA
Neurosci Lett 231:13-6. 1997b>Apamin, a bee venom toxin which blocks a Ca2+-dependent K+ current, potentiates N-methyl-D-aspartate (NMDA)-induced burst firing in dopamine neurons...
- Role of apamin-sensitive k(ca) channels for reticulospinal synaptic transmission to motoneuron and for the afterhyperpolarizationLorenzo Cangiano
Department of Neuroscience, Nobel Institute for Neurophysiology, Karolinska Institute, 17177 Stockholm, Sweden
J Neurophysiol 88:289-99. 2002..injection of 1,2-bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA; fast Ca(2+) chelator), and by apamin (selective toxin for K(Ca) channels of the SK subtype)...
- Apamin-sensitive small conductance calcium-activated potassium channels, through their selective coupling to voltage-gated calcium channels, are critical determinants of the precision, pace, and pattern of action potential generation in rat subthalamic nuNicholas E Hallworth
University of Tennessee, Anatomy and Neurobiology, Memphis, Tennessee 38163, USA
J Neurosci 23:7525-42. 2003..from postnatal day 16 (P16)-P30 rats and held at 37 degrees C] and then treated with the SK KCa channel antagonist apamin or the SK KCa channel agonist 1-ethyl-2-benzimidazolinone or the Cav channel antagonists w-omega-conotoxin GVIA (..
- Apamin improves reference memory but not procedural memory in rats by blocking small conductance Ca(2+)-activated K(+) channels in an olfactory discrimination taskC Fournier
Laboratoire de Neurobiologie des Comportements, UMR 6562, , IBHOP, Traverse Susini, 13388 Marseille, Cedex 13, France
Behav Brain Res 121:81-93. 2001b>Apamin blocks SK channels responsible for long-lasting hyperpolarization following the action potential. Using an olfactory associative task, the effect of an intracerebroventricular 0...
- Characterization of the outer pore region of the apamin-sensitive Ca2+-activated K+ channel rSK2Heike Jäger
Department of Applied Physiology, University of Ulm, Albert Einstein Allee 11, 89081 Ulm, Germany
Toxicon 43:951-60. 2004..Beside apamin, ScTX is a high affinity blocker of the SK2 channel, whereas CTX is unable to block current through SK2...
- Solution structure of apamin determined by nuclear magnetic resonance and distance geometryJ H Pease
Department of Chemistry, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
Biochemistry 27:8491-8. 1988The solution structure of the bee venom neurotoxin apamin has been determined with a distance geometry program using distance constraints derived from NMR. Twenty embedded structures were generated and refined by using the program DSPACE...
- Modulators of small- and intermediate-conductance calcium-activated potassium channels and their therapeutic indicationsHeike Wulff
Department of Medical Pharmacology and Toxicology, University of California, Davis, CA 95616, USA
Curr Med Chem 14:1437-57. 2007..1-KCa2.3 (a.k.a. SK1-SK3) and the intermediate-conductance channel KCa3.1 (a.k.a. IKCa1). The apamin-sensitive KCa2 channels contribute to the medium afterhyperpolarization and are crucial regulators of neuronal ..
- The precursors of the bee venom constituents apamin and MCD peptide are encoded by two genes in tandem which share the same 3'-exonM Gmachl
Institute of Molecular Biology, Austrian Academy of Sciences, Salzburg
J Biol Chem 270:12704-8. 1995From a cDNA library prepared from venom glands of worker bees, clones encoding the precursors of apamin and MCD peptide have been isolated. The cDNAs are similar at the 5'-ends and identical in their 3'-regions...
- Active K+ secretion through multiple KCa-type channels and regulation by IKCa channels in rat proximal colonWilliam J Joiner
Department of Internal Medicine, Yale University, 333 Cedar Street, P O Box 208019, New Haven, CT 06520, USA
Am J Physiol Gastrointest Liver Physiol 285:G185-96. 2003..In contrast, only partial inhibition was observed with the BK and SK channel inhibitors, iberiotoxin and apamin, respectively...
- Discrimination between subtypes of apamin-sensitive Ca(2+)-activated K+ channels by gallamine and a novel bis-quaternary quinolinium cyclophane, UCL 1530P M Dunn
Department of Pharmacology, University College London
Br J Pharmacol 117:35-42. 1996..were tested for their ability to block actions mediated by the small conductance, apamin-sensitive Ca(2+)-activated K+ (SKCa) channels in rat cultured sympathetic neurones and guinea-pig isolated ..
- Calcium influx via L- and N-type calcium channels activates a transient large-conductance Ca2+-activated K+ current in mouse neocortical pyramidal neuronsXiaolu Sun
Department of Pediatrics (Section of Respiratory Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
J Neurosci 23:3639-48. 2003..component of the sustained currents were Ca2+ dependent and sensitive to charybdotoxin and iberiotoxin but not to apamin, suggesting that they were mediated by large-conductance Ca2+-activated K+ (BK) channels...
- Participation of intracellular Ca2+ stores in arteriolar conducted responsesYasuaki Yashiro
First Department of Physiology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
Am J Physiol Heart Circ Physiol 285:H65-73. 2003..was mimicked by extraluminal application of tetraethylammonium or charybdotoxin but not by iberiotoxin, apamin, glibenclamide, barium, or 4-aminopirydine...
- Decreased 4-aminopyridine sensitive K+ currents in endothelial cells from hypertensive ratsTsuneaki Sadanaga
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
Hypertens Res 25:589-96. 2002..Ca2+-dependent K+ channel blockers, charybdotoxin and apamin, a voltage-dependent K+ channel blocker, 4-aminopyridine, and a non-selective K+ channel blocker, ..
- Structure, function, and endothelium-derived hyperpolarizing factor in the caudal artery of the SHR and WKY ratShaun L Sandow
Division of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT, 0200, Australia
Arterioscler Thromb Vasc Biol 23:822-8. 2003..To quantify structural and functional characteristics of the caudal artery from spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rats with particular reference to endothelium-derived hyperpolarizing factor (EDHF)...
- Small-conductance calcium-activated K+ channels are expressed in pancreatic islets and regulate glucose responsesNatalia A Tamarina
Department of Medicine, University of Chicago, Chicago, Illinois, USA
Diabetes 52:2000-6. 2003..The SK/IK channel-blockers apamin, dequalinium, and charybdotoxin caused increases in average [Ca(2+)](i) levels and in frequency of [Ca(2+)](i) ..
- The peripheral antinociceptive effect of resveratrol is associated with activation of potassium channelsV Granados-Soto
Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Mexico, DF, Mexico
Neuropharmacology 43:917-23. 2002..In contrast, charybdotoxin and apamin (large and small conductance Ca(2+) activated-K(+) channel blockers, respectively), 4-aminopyridine or ..
- Role of Ca2+-dependent potassium channels in in vitro anandamide-mediated mesenteric vasorelaxation in rats with biliary cirrhosisYing Ying Yang
Institute of Clinical Medicine, National Yang Ming University School of Medicine, Taipei, Taiwan
Liver Int 27:1045-55. 2007..to anandamide was suppressed by combinations of vascular Ca(2+)-dependent K(+) channel blockers (including apamin+charybdotoxin+iberiotoxin or apamin+TRAM-34+iberiotoxin) (TRAM-34, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole)...
- Distinct role of nitric oxide and endothelium-derived hyperpolarizing factor in renal microcirculation. Studies in the isolated perfused hydronephrotic kidneyYuri Ozawa
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
Nephron 92:905-13. 2002..In contrast, LNAME had no effect on the initial phase of ACH-induced dilation. In the presence of apamin + charybdotoxin, the initial vasodilator response to ACH (1 micromol/l) was diminished (ILA, from 108 +/- 8 to 46 +..
- SK2 encodes the apamin-sensitive Ca(2+)-activated K(+) channels in the human leukemic T cell line, JurkatH Jager
Department of Applied Physiology, University of Ulm, Albert Einstein Allee 11, D 89081, Ulm, Germany
FEBS Lett 469:196-202. 2000..The cloned and native channels are voltage-independent, Ca(2+)-activated, apamin-sensitive, show an equivalent voltage-dependent Ba(2+) block and possess a similar ion selectivity...
- Acetylcholine and ATP hyperpolarize endothelium via activation of different types of Ca(2+)-activated K+ channelsS M Marchenko
A A Bogomolets Institute of Physiology, National Academy of Science of Ukraine, Kiev
Bull Exp Biol Med 134:422-4. 2002..It was hypothesized that ATP- and acetylcholine-activated Ca(2+)-signals are spatially separated and generated in plasma membrane regions with predominant localization of SK- and IR-channels, respectively...
- A novel mechanism for the facilitation of theta-induced long-term potentiation by brain-derived neurotrophic factorEniko A Kramar
Department of Psychiatry and Human Behavior, University of California, Irvine, California 92612 1695, USA
J Neurosci 24:5151-61. 2004..b>Apamin, an antagonist of type 2 small-conductance Ca2+-activated potassium (SK2) channels, also reduced hippocampal AHPs ..
- Combination of Ca2+ -activated K+ channel blockers inhibits acetylcholine-evoked nitric oxide release in rat superior mesenteric arteryE Stankevicius
Department of Pharmacology, Faculty of Health Sciences, University of Aarhus, Aarhus C, Denmark
Br J Pharmacol 149:560-72. 2006..KEY RESULTS: A combination of apamin plus charybotoxin, which are, respectively, blockers of small-conductance and of intermediate- and large-..
- Effects of increased intracellular Cl- concentration on membrane responses to acetylcholine in the isolated endothelium of guinea pig mesenteric arteriesYoshimichi Yamamoto
Laboratory of Physiology, Nagoya City University School of Nursing, Mizuho ku, Nagoya, 467 8601, Japan
J Physiol Sci 57:31-41. 2007..The K(+) current was blocked by a combination of charybdotoxin and apamin and appears to result from the opening of IK(Ca) and SK(Ca) channels...
- Somatostatinergic modulation of firing pattern and calcium-activated potassium currents in medium spiny neostriatal neuronsE Galarraga
Departamento de Biofisica, Instituto de Fisiologia Celular, Universidad Nacional Autonoma de Mexico, PO Box 70 253, Mexico City, DF 04510, Mexico
Neuroscience 146:537-54. 2007..Therefore, somatostatin actions appear to be the entrainment of projection neurons to the rhythms generated by some interneurons. Somatostatin is then capable of modifying the processing and output of the neostriatum...
- Smooth muscle mediates circumferential conduction of hyperpolarization and relaxation to focal endothelial cell activation in large coronary arteriesStavros Selemidis
Department of Pharmacology, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia
Naunyn Schmiedebergs Arch Pharmacol 375:85-94. 2007..of endothelium-dependent hyperpolarization-the Ca2+ -activated potassium channel (KCa) channel inhibitors, apamin and charybdotoxin...
- Endothelium-derived hyperpolarization factor (EDHF) is up-regulated in a pig model of acute liver failureSveinung Ekse
Department of Anesthesiology and Intensive Care, University of Tromsø, University Hospital Northern Norway, Tromsø, Norway
Scand J Gastroenterol 42:356-65. 2007....
- Activity of endothelium-derived hyperpolarizing factor is augmented in monocrotaline-induced pulmonary hypertension of rat lungsYoshiteru Morio
Department of Respiratory Medicine, Juntendo University School of Medicine, Tokyo, Japan
J Vasc Res 44:325-35. 2007..Inhibition of EDHF with a combination of K(Ca) blockers, charybdotoxin (50 nM) plus apamin (50 nM), increased baseline vascular tone in MCT-induced hypertensive lungs...
- Type 1 diabetes and hypercholesterolaemia reveal the contribution of endothelium-derived hyperpolarizing factor to endothelium-dependent relaxation of the rat aortaWachirawadee Malakul
Department of Physiology, Faculty of Pharmacy, Mahidol University, Thailand
Clin Exp Pharmacol Physiol 35:192-200. 2008..to inhibition by L-NNA or ODQ, but abolished by additional inhibition of K(Ca) channels with charybdotoxin plus apamin. 4...
- Negative inotropic effect of selective AT2 receptor stimulation and its modulation by the endocardial endotheliumPaulo Castro-Chaves
Department of Physiology, Faculty of Medicine, Alameda Prof Hernani Monteiro, 4200 319 Porto, Portugal
Eur J Pharmacol 578:261-9. 2008..activation was also performed in presence of NG-nitro-L-Arginine, indomethacin, proadifen, hydroxocobalamin, apamin plus charybdotoxin, Hoe-140 or PD-123,319, as well as, after endocardial endothelium removal...
- Analysis of L-NAME-dependent and -resistant responses to acetylcholine in the ratPaul A Dabisch
Department of Pharmacology, Tulane University Health Sciences Center, New Orleans, LA 70112, USA
Am J Physiol Heart Circ Physiol 294:H688-98. 2008..The calcium-activated potassium (K(Ca)) antagonists charybdotoxin (ChTX) and apamin decreased the magnitude but not the duration of the hindlimb vasodilator response to ACh...
- Ca2+-activated K+ channels in murine endothelial cells: block by intracellular calcium and magnesiumJonathan Ledoux
Department of Pharmacology, College of Medicine, University of Vermont, Burlington 05405, USA
J Gen Physiol 131:125-35. 2008..However, blockers of IK(Ca) channels, charybdotoxin (ChTX), and of SK(Ca) channels, apamin (Ap), significantly reduced the whole-cell current...
- Competition between calcium-activated K+ channels determines cholinergic action on firing properties of basolateral amygdala projection neuronsJohn M Power
Queensland Brain Institute, The University of Queensland, St Lucia, Queensland 4072, Australia
J Neurosci 28:3209-20. 2008..These results suggest that competition between cholinergic suppression of the sI(AHP) and cholinergic activation of the SK channels shapes the AHP and spike-frequency adaptation...
- Emergence of intrinsic bursting in trigeminal sensory neurons parallels the acquisition of mastication in weanling ratsFrédéric Brocard
Universite de Montreal, Pavillon Paul Desmarais, C P 6128, Succursale Centre Ville, Montreal, Quebec H3C 3J7, Canada
J Neurophysiol 96:2410-24. 2006..Lowering extracellular [Ca(2+)] increased both I(NaP) and probability of bursting. We suggest that these mechanisms underlie burst generation in mastication and that similar processes may be found in other motor pattern generators...
- EDHF-mediated rapid restoration of hypotensive response to acetylcholine after chronic, but not acute, nitric oxide synthase inhibition in ratsKaushik M Desai
Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
Eur J Pharmacol 546:120-6. 2006..determined in anesthetized rats before and after acute intravenous infusion of either L-NAME or a combination of apamin plus charybdotoxin that would selectively inhibit EDHF...
- A novel scorpion toxin blocking small conductance Ca2+ activated K+ channelChen-Qi Xu
Institute of Neuroscience, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
Toxicon 43:961-71. 2004..BmSKTx1 selectively inhibited apamin-sensitive SK currents in RACC with Kd of 0.72 microM and Hill coefficient of 2.2...
- Contribution of Ca2+-activated K+ channels to hyperpolarizing after-potentials and discharge pattern in rat supraoptic neuronesW Greffrath
Institute of Physiology and Pathophysiology, Gutenberg University, Mainz, Germany
J Neuroendocrinol 16:577-88. 2004..The sHAP and spike-frequency adaptation were blocked by cadmium, as well as by the SK channel antagonist apamin. The fHAP was attenuated by the BK channel antagonist iberiotoxin (IbTX), by the BK/IK channel antagonist ..
- Ca2+-dependent K+ channels from rat olfactory cilia characterized in planar lipid bilayersKaren Castillo
Department of Biology, Faculty of Sciences, University of Chile, PO Box 653, Santiago, Chile
FEBS Lett 579:1675-82. 2005..All four ciliary KCas were observed: The 16 pS channel, K0.5,Ca=40 microM and apamin-sensitive; the 30 and 50 pS channel, K0...
- Nitric oxide mediates abnormal responsiveness of thyroid arteries in methimazole-treated patientsJoaquin Ortega
Department of Surgery, Hospital Clínico Research Unit, University of Valencia, Spain
Eur J Endocrinol 152:551-6. 2005..We studied the intervention of nitric oxide (NO), prostacyclin and endothelium-derived hyperpolarizing factor (EDHF) in mediating responses to acetylcholine in thyroid arteries from euthyroid and methimazole-treated (MT) patients...
- The effects of Delta9-tetrahydrocannabinol in rat mesenteric vasculature, and its interactions with the endocannabinoid anandamideSaoirse E O'Sullivan
School of Biomedical Sciences, University of Nottingham, Queen s Medical Centre, Nottingham NG7 2UH
Br J Pharmacol 145:514-26. 2005..to THC was inhibited by high K+ buffer, and by the following K+ channel inhibitors: charybdotoxin (100 nM), apamin (500 nM) and barium chloride (30 microM), but not by 4-aminopyridine, glibenclamide or tertiapin...
- Cloning and characterization of SK2 channel from chicken short hair cellsT M Matthews
Department of Biomedical Engineering, The Center for Hearing Sciences, Johns Hopkins University School of Medicine, 521 Traylor Building, 720 Rutland Ave, Baltimore, MD 21205 2195, USA
J Comp Physiol A Neuroethol Sens Neural Behav Physiol 191:491-503. 2005..reptiles and amphibians, acetylcholine released from efferent neurons inhibits hair cells via activation of an apamin-sensitive, calcium-dependent potassium current...
- Pharmacological evidence for the activation of Ca2+-activated K+ channels by meloxicam in the formalin testMario I Ortiz
Área Académica de Medicina del Instituto de Ciencias de la Salud, Universidad Autonoma del Estado de Hidalgo, Pachuca, Hidalgo, Mexico
Pharmacol Biochem Behav 81:725-31. 2005..However, local peripheral pretreatment of the paw with charybdotoxin and apamin (large- and small-conductance Ca2+-activated K+ channel inhibitors, respectively), 4-aminopyridine and ..
- 1-Ethyl-2-benzimidazolinone (EBIO) suppresses epileptiform activity in in vitro hippocampusJulieta Garduño
Instituto Cajal, CSIC, Av Dr Arce 37, 28002 Madrid, Spain
Neuropharmacology 49:376-88. 2005....
- Reduced hyperpolarization in endothelial cells of rabbit aortic valve following chronic nitroglycerine administrationNobuyoshi Kusama
Department of Cellular and Molecular Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Kawasumi 1, Nagoya, Aichi 467-8601, Japan
Br J Pharmacol 146:487-97. 2005..ACh (0.03-3 microM) induced a hyperpolarization through activations of both apamin- and charybdotoxin-sensitive Ca2+-activated K+ channels (K(Ca)) in rabbit AVECs...
- SK channel regulation of dendritic excitability and dendrodendritic inhibition in the olfactory bulbBrady J Maher
Vollum Institute, Oregon Health and Science University, Portland, 97239, USA
J Neurophysiol 94:3743-50. 2005..brain slices from PND 14-21 mice, long step depolarizations (100 ms) in the mitral cell soma evoked a cadmium- and apamin-sensitive outward SK current lasting several hundred milliseconds...
- Ca2+-activated K+-current density is correlated with soma size in rat vestibular-afferent neurons in cultureAgenor Limon
Institute of Physiology, Autonomous University of Puebla, Mexico
J Neurophysiol 94:3751-61. 2005....
- Estrogen and the Ca2+-mobilizing agonist ATP evoke acute NO synthesis via distinct pathways in an individual human vascular endothelium-derived cellJian zhong Sheng
Smooth Muscle Research Group, Libin Cardiovascular Institute and Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
Am J Physiol Cell Physiol 294:C1531-41. 2008..inhibited by the respective small-conductance and intermediate-conductance calcium- activated K+ channel blockers apamin and charybdotoxin...
- Medium afterhyperpolarization and firing pattern modulation in interneurons of stratum radiatum in the CA3 hippocampal regionN Savic
Neuroscience Programme and Istituto Nazionale Fisica della Materia Unit, International School for Advanced Studies SISSA, 34014 Trieste, Italy
J Neurophysiol 85:1986-97. 2001..Tail currents presented a fast Ca(2+)-activated and apamin-sensitive component (I(AHP)) and were further reduced by carbachol...
- ATP-stimulated Ca(2+)-activated K(+) efflux pathway and differentiation of human placental cytotrophoblast cellsL H Clarson
Academic Unit of Child Health, University of Manchester, St Mary s Hospital, Manchester M13 0JH, United Kingdom
Am J Physiol Regul Integr Comp Physiol 282:R1077-85. 2002..The dependency of this pathway on [Ca(2+)](o) is greater in the 66-h multinucleate syncytiotrophoblast-like cells, suggesting that the mechanism for Ca(2+) entry may be altered during differentiation of trophoblast cells...
- Determinants of renal microvascular response to ACh: afferent and efferent arteriolar actions of EDHFXuemei Wang
Smooth Muscle Research Group, Department of Pharmacology and Therapeutics, University of Calgary, Calgary, Alberta, Canada
Am J Physiol Renal Physiol 282:F124-32. 2002..Charybdotoxin (10 nmol/l) and apamin (1...
- Cellular target of voltage and calcium-dependent K(+) channel blockers involved in EDHF-mediated responses in rat superior mesenteric arteryP Ghisdal
Laboratoire de Pharmacologie, , UCL 5410, Avenue Hippocrate, 54 - B 1200 Bruxelles, Belgium
Br J Pharmacol 134:1021-8. 2001..01 - 3 microM) was abolished by a combination of charybdotoxin (ChTX, 0.1 microM) plus apamin (Apa, 0.1 microM) and was inhibited by 68+/-6% (n=6) by 4-aminopyridine (4-AP, 5 mM). 3. ACh(0...
- Rapidly inactivating and non-inactivating calcium-activated potassium currents in frog saccular hair cellsC E Armstrong
Institute of Neuroscience, University of Oregon, Eugene, 97403-1254, USA
J Physiol 536:49-65. 2001..Both were blocked by iberiotoxin, a specific blocker of large-conductance K(Ca) channels (BK), but not by apamin, a specific blocker of small-conductance K(Ca) channels. 4...
- The pharmacology of hSK1 Ca2+-activated K+ channels expressed in mammalian cell linesM Shah
Department of Pharmacology, University College London, Gower Street, London, WC1E 6BT
Br J Pharmacol 129:627-30. 2000..In these cell types, hSK1 forms an apamin-sensitive channel with an IC(50) for apamin of 8 nM in HEK293 cells and 12 nM in COS-7 cells...
- Pharmacological evidence for the activation of potassium channels as the mechanism involved in the hypotensive and vasorelaxant effect of dioclein in rat small resistance arteriesS F Cortes
Laboratório de Farmacologia Cardiovascular, Departamento de Farmacologia ICB Universidade Federal de Minas Gerais 31270 901, Belo Horizonte Brazil
Br J Pharmacol 133:849-58. 2001..b>Apamin (1 microM) reduced the E(max) without affecting the IC(50)...
- Cloning and functional expression of a liver isoform of the small conductance Ca2+-activated K+ channel SK3E T Barfod
Department of Medicine, University of Vermont, Burlington, VT 05405, USA
Am J Physiol Cell Physiol 280:C836-42. 2001..expressed 10 pS K+ channels that were Ca2+ dependent (EC(50) 630 nM) and were blocked by the SK channel inhibitor apamin (IC(50) 0.6 nM); whole cell SK3 currents inactivated at membrane potentials more positive than -40 mV...
- Activation of beta-adrenoceptors opens calcium-activated potassium channels in astroglial cellsH Muyderman
Institute of Neurobiology and Institute of Clinical Neuroscience, , Box 420, SE-405 30, , Sweden
Neurochem Int 38:269-76. 2001..was blocked by external tetraethylammonium (TEA, 10 mM) and charybdotoxin (ChTX, 10 nM), but was not affected by apamin (50 nM)...
- Chemical anoxia activates ATP-sensitive and blocks Ca(2+)-dependent K(+) channels in rat dorsal vagal neurons in situA Kulik
II. Physiologisches Institut, , Germany
Neuroscience 110:541-54. 2002..current was abolished by the K(ATP) channel blocker tolbutamide, but not changed by the SK and BK channel blockers apamin or tetraethylammonium...
- K(Ca) channel blockers reveal hyperpolarization and relaxation to K+ in rat isolated mesenteric arteryKim A Dora
Department of Pharmacy and Pharmacology, University of Bath, 5W Building, Bath BA2 7AY, UK
Am J Physiol Heart Circ Physiol 283:H606-14. 2002..effect on arteries contracted >10 mN, unless 100 nM iberiotoxin (IbTX), 100 nM charybdotoxin (ChTX), and/or 50 nM apamin were present...
- K+ currents generated by NMDA receptor activation in rat hippocampal pyramidal neuronsMala M Shah
Department of Pharmacology, University College London, London WC1E 6BT, United Kingdom
J Neurophysiol 87:2983-9. 2002..4 s. In 43% of those cells exhibiting an outward current, SK channel inhibitors, UCL 1848 (100 nM) and apamin (100 nM) abolished the outward current...
- Charybdotoxin-sensitive small conductance K(Ca) channel activated by bradykinin and substance P in endothelial cellsM Sollini
Department of Zoology and Animal Biology, Sciences III, 30 quai E. Ansermet 1211 Geneva 4, Switzerland
Br J Pharmacol 136:1201-9. 2002..A large part of this current was insensitive to iberiotoxin and apamin. The aim of the present study was to characterize the K(Ca) channel responsible for this current...
- Differential regulation of SK and BK channels by Ca(2+) signals from Ca(2+) channels and ryanodine receptors in guinea-pig urinary bladder myocytesGerald M Herrera
Department of Molecular Physiology, University of Vermont College of Medicine, Burlington, VT 05405, USA
J Physiol 541:483-92. 2002..To characterize the role of SK channels in UBSM, the effects of the SK channel blocker apamin on phasic contractions were examined...
- Developmental regulation of small-conductance Ca2+-activated K+ channel expression and function in rat Purkinje neuronsLorenzo A Cingolani
Max-Planck-Institute for Experimental Medicine, , Germany
J Neurosci 22:4456-67. 2002..These results provide the first evidence of the developmental regulation and function of SK channels in central neurons...
- Bradykinin B2 receptors and coupling mechanisms in the smooth muscle of the guinea-pig taenia caeciJ L Field
Biomedical Sciences Division, King s College London, Chelsea, London
Br J Pharmacol 113:607-13. 1994..In Krebs solution, the Ca(2+)-activated K(+)-channel blocker, apamin (10 nM), abolished relaxant responses...
- The role of tachykinin NK1 and NK2 receptors in atropine-resistant colonic propulsion in anaesthetized guinea-pigsA Lecci
Pharmacology Research Department, Menarini Ricerche S p A, Florence, Italy
Br J Pharmacol 124:27-34. 1998..3. In atropine-treated animals (6 micromol kg(-1), i.v., plus infusion of 1.8 micromol h(-1)), apamin (30 nmol kg(-1), i.v...
- INTRACELLULAR STUDY OF ETHANOL EFFECTS ON BRAIN NEURONSMark Brodie; Fiscal Year: 2009..Ethanol excitation is completely blocked by quinidine, but not by the other K channel blockers apamin, tetraethylammonium, barium or cesium...
- INTRACELLULAR STUDY OF ETHANOL EFFECTS ON BRAIN NEURONSMark S Brodie; Fiscal Year: 2010..Ethanol excitation is completely blocked by quinidine, but not by the other K channel blockers apamin, tetraethylammonium, barium or cesium...
- ENKEPHALINS--NEUROPHARMACOLOGY AND ABUSE POTENTIALWilliam Dewey; Fiscal Year: 2000..demonstrated that acute morphine analgesia is antagonized by blockers of potassium channels such as glyburide and apamin. Consistent with this are in vitro observations that K+ channel antagonists prevent mu opioid-stimulated k+ efflux ..
- SK CHANNELS IN HYPEREXCITABLE SKELETAL MUSCLEJohn Adelman; Fiscal Year: 2001..The cellular hallmark of these conditions is the appearance of receptors for the peptide toxin apamin, a potent blocker of small conductance calcium-activated potassium (SK) channels...
- EICOSANOIDS, VASCULAR TONE AND BLOOD PRESSUREWILLIAM BRYSON CAMPBELL; Fiscal Year: 2010..relaxations and hyperpolarizations that are blocked by LO inhibitors, high extracellular K ([K]o) and apamin. Thus, the endothelium-dependent relaxations and hyperpolarizations to ACh and AA are mediated by a LO metabolite ..
- EICOSANOIDS, VASCULAR TONE AND BLOOD PRESSUREWilliam Campbell; Fiscal Year: 2007..endothelium-dependent relaxations and hyperpolarizations that are blocked by LO and CYP inhibitors, high [K]o and apamin. Thus, these relaxations and hyperpolarizations are mediated by a LO metabolite of AA...
- SK channels: Roles and mechanisms for dendritic excitability and plasticityJames G Maylie; Fiscal Year: 2010b>Apamin-sensitive small conductance Ca2+-activated K+ channels (SK channels) are implicated in the molecular and cellular mechanisms underlying learning and memory, and blocking SK channels in vivo affects hippocampal dependent learning ..
- Investigations into the mouse olivocochlear systemDouglas Vetter; Fiscal Year: 2007..The mechanisms of action may include phosphorylation and inactivation of the sK2 calcium-activated apamin-sensitive potassium channel...
- Molecular physiology of SK2 channels in CA1 neuronsJohn Adelman; Fiscal Year: 2007..Blocking SK channels with apamin reduces the stimulus intensity that is required to induce NMDA receptor-dependent long-term potentiation at ..
- CLONING/CHARACTERIZATING A MYOTONIC DYSTROPHY LOCUSLAURA RANUM; Fiscal Year: 2004..changes found in DM2 are part of a common pathway also affected in DM1; 5) to determine whether molecular changes affecting RNA splicing, CUG binding proteins, and apamin receptors are similar to those found in DM1.
- SMALL CONDUCTANCE CALCIUM ACTIVATED POTASSIUM CHANNELSJohn Adelman; Fiscal Year: 2001..Subtypes of SK channels may be distinguished by different sensitivities to the bee venom peptide toxin apamin. Application of apamin to regions of the brain alters physiologically important processes, such as sleep patterns ..
- CNS DA NEURONS--CELLULAR BASIS OF PATTERNED ACTIVITYPaul Shepard; Fiscal Year: 2002..In the second specific aim, current and voltage clamp techniques will be used to test the hypothesis that an apamin-insensitive Ca2+-dependent conductance: (1) contributes to the hyperpolarization that terminates the plateau phase ..
- Memory modulation by SK channelsROBERT WILLIAM STACKMAN; Fiscal Year: 2010..Our preliminary findings indicate that the SK channel blocker, apamin enhances memory, while the SK channel activator, 1-EBIO impairs memory...
- Memory modulation by SK channelsRobert Stackman; Fiscal Year: 2009..Our preliminary findings indicate that the SK channel blocker, apamin enhances memory, while the SK channel activator, 1-EBIO impairs memory...
- MOLECULAR PHYSIOLOGY OF SK CHANNELS IN CA1 NEURONSJohn Adelman; Fiscal Year: 2003..In CA1 hippocampal pyramidal neurons (HPNs) the AHP has two kinetic components. The medium AHP is apamin-sensitive and is not affected by neurotransmitter-induced second messengers, while the slow AHP is insensitive to ..
- ETHANOL-NEUROTRANSMITTER INTERACTIONS IN BRAIN NEURONSMark Brodie; Fiscal Year: 2007..SK can be reduced by drugs like apamin or by depletion of intracellular calcium...