Affiliation: University of Duisburg-Essen
- NHE3 in the human brainstem: implication for the pathogenesis of the sudden infant death syndrome (SIDS)?Martin Wiemann
University of Duisburg Essen, Department of Physiology
Adv Exp Med Biol 605:508-13. 2008..Evaluation of signals from NHE3 RT-PCR showed higher values for the SIDS collective than for the control group. We suggest that the level of NHE3 expression in brainstem tissue may contribute to the vulnerability of infants for SIDS...
- The NHE3 inhibitor AVE1599 stimulates phrenic nerve activity in the ratM Wiemann
Department of Physiology, University of Duisburg Essen, Essen, Germany
J Physiol Pharmacol 59:27-36. 2008..5 +/- 9.2 and 58.6 +/- 10.0% after 10 and 30 min (n = 6), respectively, but did not abolish hypercapnic responses. We conclude that AVE1599 augments central respiratory drive in the WHBP via NHE3 but not NHE1 inhibition...
- Intracellular pH modulates spontaneous and epileptiform bioelectric activity of hippocampal CA3-neuronesU Bonnet
Rheinische Kliniken, Universitatsklinik fur Psychiatrie und Psychotherapie, POB 103043, D 45030, Essen, Germany
Eur Neuropsychopharmacol 10:97-103. 2000..Together, these results indicate that intracellular acidification inhibits bioelectric activity of hippocampal CA3-neurones. This supports the hypothesis that pH(i) contributes to the control of cortical excitability...
- A novel inhibitor of the Na+/H+ exchanger type 3 activates the central respiratory CO2 response and lowers the apneic thresholdH Kiwull-Schöne
Department of Physiology, Faculty of Medicine, Ruhr University, Bochum, Germany
Am J Respir Crit Care Med 164:1303-11. 2001..0001). These in vivo results are compatible with the effects of NHE3 inhibition on chemosensitive brainstem neurons in vitro. Moreover, rhythmogenesis is supported through NHE3 inhibition by lowering the threshold PCO2 for central apnea...
- Pharmacological impact on loop gain properties to prevent irregular breathingH Kiwull-Schöne
Department of Physiology, Ruhr University Bochum, Germany
J Physiol Pharmacol 59:37-45. 2008..Generally, effective treatment should aim at a low system loop gain, by reducing respiratory chemosensitivity, improving blood gases and preventing low metabolic rates...
- Antiepileptic activity of zonisamide on hippocampal CA3 neurons does not depend on carbonic anhydrase inhibitionJan Thone
Institute of Physiology, University of Duisburg Essen, Essen, Germany
Epilepsy Res 79:105-11. 2008..Clinically relevant concentrations of ZNS strongly inhibit 4-AP induced epileptiform activity of hippocampal CA3 neurons in vitro, but this effect was unlikely based on carbonic anhydrase inhibition or changes of neuronal pHi...
- The endogenous alkaloid harmane: acidifying and activity-reducing effects on hippocampal neurons in vitroUdo Bonnet
Department of Addictive Behaviour and Addiction Medicine, University of Duisburg Essen, Virchowstr 174, D 45147 Essen, Germany
Prog Neuropsychopharmacol Biol Psychiatry 32:362-7. 2008..As harmane affects neuronal activity and viability and because both parameters are strongly influenced by intracellular pH (pH(i)), we tested whether effects of harmane are correlated with altered pH(i) regulation...
- Serotonin but not zonisamide inhibits theophylline-induced epileptiform activity in guinea pig hippocampal CA3 neuronsJan Thone
Institute of Physiology, University of Duisburg Essen, Hufelandstrasse 55, 45122 Essen, Germany
Epilepsy Res 76:73-6. 2007..In contrast, ZNS failed to alter epileptiform bursting. We conclude that 5-HT augmenting effects of ZNS are missing or are not sufficient to inhibit epileptiform activity in hippocampal slice preparations...
- Modulatory effects of neuropsychopharmaca on intracellular pH of hippocampal neurones in vitroUdo Bonnet
Department of Psychiatry and Psychotherapy, LVR Hospital of Essen, University of Duisburg Essen, Essen, Germany
Br J Pharmacol 159:474-83. 2010..As moclobemide, an antidepressant, and also some antiepileptic drugs can reduce neuronal pHi in hippocampus slices in vitro, we screened a panel of currently used neuropsychopharmaca for comparable effects...
- Carbonic anhydrase inhibitor sulthiame reduces intracellular pH and epileptiform activity of hippocampal CA3 neuronsTobias Leniger
Department of Neurology, University of Essen, Essen, Germany
Epilepsia 43:469-74. 2002..The aim of the study was to elucidate the mode of action of sulthiame with respect to possible changes of intracellular pH (pHi) that might develop along with sulthiame's anticonvulsant properties...
- Organic and inorganic calcium antagonists inhibit veratridine-induced epileptiform activity in CA3 neurons of the guinea pigMark Christian Link
Institute of Physiology, University of Duisburg Essen, Hufelandstr 55, 45122 Essen, Germany
Epilepsy Res 78:147-54. 2008..Due to the effects of both calcium antagonists we conclude that veratridine-induced epileptiform activity depends not only on sodium, but also on calcium currents...
- Brainstem NHE-3 expression and control of breathingMartin Wiemann
Department of Physiology, University of Essen, Essen, Germany
Adv Exp Med Biol 551:39-44. 2004
- Enhancement of connexin 43 expression increases proliferation and differentiation of an osteoblast-like cell lineB Gramsch
Department of Physiology, University of Essen, Essen, D-45122, Germany
Exp Cell Res 264:397-407. 2001..We conclude that enhanced gap-junctional coupling via Cx43 significantly promotes proliferation and differentiation of UMR cells...
- Alteration of intracellular pH and activity of CA3-pyramidal cells in guinea pig hippocampal slices by inhibition of transmembrane acid extrusionU Bonnet
Rheinische Kliniken, Universitatsklinik fur Psychiatrie und Psychotherapie, Universität GH Essen, Virchowstr 174, D 45147, Essen, Germany
Brain Res 872:116-24. 2000....
- Expression of anion exchanger 3 influences respiratory rate in awake and isoflurane anesthetized miceS Meier
Klinik für Anästhesiologie und Intensivmedizin, Universitatsklinikum Essen, Essen, Germany
J Physiol Pharmacol 58:371-8. 2007..Recovery from isoflurane anesthesia in respect to RR regaining baseline values was more pronounced in AE3 KO. Results show that AE3 expression profoundly influences control of breathing in mice...
- Sodium/Proton exchanger 3 in the medulla oblongata and set point of breathing controlMartin Wiemann
Department of Physiology, University of Duisburg Essen, 45122 Essen, Germany
Am J Respir Crit Care Med 172:244-9. 2005..In vivo inhibition of the sodium/proton exchanger 3 (NHE3) in chemosensitive neurons of the ventrolateral brainstem augments central respiratory drive in anesthetized rabbits...
- Role of brainstem sodium/proton exchanger 3 for breathing control during chronic acid base imbalanceHeidrun Kiwull-Schöne
Department of Physiology, Ruhr University, 44780 Bochum, Germany
Am J Respir Crit Care Med 176:513-9. 2007..Moreover, levels of NHE3 expression are inversely correlated to interindividual differences of baseline ventilation in conscious rabbits...
- Tentative role of the Na+/H+ exchanger type 3 in central chemosensitivity of respirationHeidrun Kiwull-Schöne
Department of Physiology, Ruhr University, D 44780 Bochum, Germany
Adv Exp Med Biol 536:415-21. 2003
- Valproate acidifies hippocampal CA3-neurons--a novel mode of actionUdo Bonnet
Rheinische Kliniken, Universitatsklinik fur Psychiatrie und Psychotherapie, Virchowstrasse 174, D 45147 Essen, Germany
Eur Neuropsychopharmacol 12:279-85. 2002....
- Topiramate modulates pH of hippocampal CA3 neurons by combined effects on carbonic anhydrase and Cl-/HCO3- exchangeTobias Leniger
Department of Neurology, University of Essen, Hufelandstr 55, 45122 Essen, Germany
Br J Pharmacol 142:831-42. 2004..The apparent decrease of steady-state pHi may contribute to the anticonvulsive property of TPM...
- NHE3 Na+/H+ exchanger supports proximal tubular protein reabsorption in vivoMichael Gekle
Physiologisches Institut, Universitat Wurzburg, Germany
Am J Physiol Renal Physiol 287:F469-73. 2004..Thus a reduction in NHE3 activity or abundance causes tubular proteinuria. These data show that NHE3 supports proximal tubular RME of filtered proteins in vivo...
- Levetiracetam inhibits Na+-dependent Cl-/HCO3- exchange of adult hippocampal CA3 neurons from guinea-pigsTobias Leniger
Department of Neurology, University of Essen, Hufelandstr 55, Essen 45122, Germany
Br J Pharmacol 142:1073-80. 2004..These data show that LEV at clinically relevant concentrations inhibits Na+-dependent Cl-/HCO3- exchange, lowers neuronal pHi, and thereby may contribute to its anticonvulsive activity...
- Sodium and chloride absorptive defects in the small intestine in Slc26a6 null miceUrsula Seidler
Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
Pflugers Arch 455:757-66. 2008..The data strongly suggests that Slc26a6 acts in concert with NHE3 in electroneutral salt absorption in the small intestine. Slc26a6 also serves to absorb Cl(-) during glucose-driven salt absorption...
- Paroxysmal depolarization shifts (PDS) induce non-synaptic responses in neighboured neurons (buccal ganglia, Helix pomatia)Ulrich Altrup
Institute of Experimental Epilepsy Research, University of Munster, Hüfferstrasse 68, D 48149 Munster, Germany
Brain Res 972:186-96. 2003..Since PDS-RD could themselves trigger PDS, PDS-RD may provide a new basic mechanism of synchronizing epileptic activity of neighboured neurons within an epileptic focus...
- NHE3 inhibition by cAMP and Ca2+ is abolished in PDZ-domain protein PDZK1-deficient murine enterocytesAyhan Cinar
Hannover Medical School, Department of Gastroenterology and Hepatology, Carl Neuberg Str 1, 30625 Hannover, Germany
J Physiol 581:1235-46. 2007..It leaves NHE3 inhibition by hyperosmolarity intact, suggesting an important and selective role for PDZK1 in the agonist-mediated regulation of intestinal NHE3 activity...
- Loop gain of respiratory control upon reduced activity of carbonic anhydrase or Na+/H+ exchangeHeidrun Kiwull-Schöne
Dept of Physiology, Ruhr University D 44780 Bochum, Germany
Adv Exp Med Biol 580:239-44; discussion 351-9. 2006
- Modulation of voltage-gated channel currents by harmaline and harmaneFrank Splettstoesser
, , , Hufelandstrasse 55, 45122 Essen, Germany
Br J Pharmacol 144:52-8. 2005..We conclude that harmaline and harmane are modulators of I(Ca(V)) in vitro. This might be related to their neuroprotective effects...
- Mice with a targeted disruption of the Cl-/HCO3- exchanger AE3 display a reduced seizure thresholdMoritz Hentschke
Department of Human Genetics, UKE Hamburg, Butenfeld 42, 22529 Hamburg, Germany
Mol Cell Biol 26:182-91. 2006..These findings strongly support the hypothesis that AE3 modulates seizure susceptibility and, therefore, are of significance for understanding the role of intracellular pH in epilepsy...