purinergic receptors

BACKGROUND: Platelets (PLTs) contain purinergic receptors for ATP (P2X1) and ADP (P2Y1 and P2Y12) that rapidly desensitize upon stimulation with these nucleotides...

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..We have collected evidence for the involvement of metabotropic purinergic receptors in proliferation induction of undifferentiated and neural progenitor cells by using a BrdU-incorporation ..

..I also discuss the current status of the field, including recent interest in the pathophysiology of purinergic signalling and its therapeutic potential...

..Among the proteins important for modulating the inflammatory function of microglia are the P2 purinergic receptors for which extracellular adenine nucleotides, such as ATP, are ligands...

..Finally the purinoceptor subtypes expressed on astrocytes, oligodendrocytes, Schwann cells, microglia, Müller cells and enteric glial cells will be summarized as well as evidence for non-lytic release of ATP from glial cells...

..Thus, diffusible factors released from activated microglia by the stimulation of purinergic receptors may have an important role in the development of neuropathic pain...

..We observed that P2X1, P2X2, P2X4 and P2X7 subtypes, but not P2X3, P2X5 and P2X6 subtypes, are present on B lymphocytes...

..In conclusion, the NHNE cells express functionally active P2Y2, P2Y6, and P2Y11 receptors in a membrane-specific pattern, which may play an important role in the control of mucin and fluid secretion in NHNE cells...

..An intracellular Ca(2+)-releasing P2U-type purinoceptor is specifically localized to adrenal endothelial cells, while a subpopulation of chromaffin cells expresses a non-P2X, non-P2Y subtype exclusively coupled to Ca2+ influx...

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We investigated the use of purinergic receptors as a new treatment modality for nonmelanoma skin cancers. Purinergic receptors, which bind adenosine 5'-tri-phosphate, are expressed on human cutaneous keratinocytes...

..millimolar levels of ATP which is coreleased with catecholamines upon stimulation and the cells express purinergic receptors. We were interested to determine whether autoinhibition produced by ATP binding to purinergic receptors ..

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..Both the ion channels and the receptors seemed to be located in the cumulus cells, which transmit their corresponding electrical signals to the oocyte via gap junction channels...

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..The cloning of the P2Y(12) receptor and its subsequent knockout in mice promises further understanding of its downstream signaling events...

..01) and 1000 microm ATP (p<0.001) on cell number. These results imply that different purinergic receptors have different functional roles in the human epidermis with P2Y1 and P2Y2 receptors controlling ..

..These findings suggest that microglial cells in situ express different purinergic receptors with distinct sensitivity and functional coupling...

We have studied modulation of purinergic receptors (P(2Y) and P(2X) subtypes) on changes in intracellular Ca(2+) [Ca(2+)](i) and expression and production of COX-2 in human microglia...

..are particularly sensitive to neural and paracrine factors, in this report we studied the role of purinergic receptors and extracellular ATP, which can be released from nerve terminals and beta-cell secretory granules...

..Involvement of P2X purinergic receptors (P2XR) in this response was anticipated, because ATP stimulation of vasopressin release from hypothalamo-..

..We have taken advantage of the actions of the purinergic agonists ATP and UTP on cytosolic free Ca2+ concentration ([Ca2+]i) to determine whether P2X and P2Y receptors might be asymmetrically distributed among AD and NA chromaffin cells...

..Current developments of compounds for the therapeutic treatment of both visceral and neuropathic pain are discussed...

b>Purinergic receptors are expressed in the membrane of the follicular cell layer that communicates with the Xenopus oocyte...

..In conclusion, extracellular ATP activates purinergic receptors and induces arrhythmic activity through modifications of Ca2+ homeostasis and an activation of depolarizing ..

..Activation of this receptor might lead to stimulation of Cl- secretion in amiloride pretreated normal but not CF cells...

..Collectively, our data suggest that the orchestrated activation of distinct P2Y and P2X receptors modulates skin inflammation...

..CONCLUSIONS: Allopurinol and captopril have a therapeutic effect on granulomatous disorders by a direct action on monocyte/macrophage lineage cells partly through downregulation of ICAM-1 and P2X7 receptor...

..These findings suggest that glucagon affects the hepatic membrane potential partly by inducing the formation and release of leukotrienes and release of ATP acting on purinergic receptors of the liver cell membrane.

..Thus, ATP acting at multiple purinergic receptors, either directly on neurons (e.g...

..Our data indicate that p90RSK downstream of ERK1/2 is the molecular target for ROS generated through stimulation of purinergic receptors by ATP.

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..This is a novel pathway for the induction of cytokines in microglia...

..The low number of functional P2 receptors in acini might be related to the fact that they release ATP. Thereby acini would avoid autocrine stimulation and initiation of autodigestive processes, such as occurs in pancreatitis...

..CONCLUSION: The rapid loss of adenine nucleotides after PHx generates early stress signals that contribute to the onset of liver regeneration...

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..In addition, VIP may be involved in the neurotransmitter in the hamster proximal colon...

..The roles of released ATP and ADP were elucidated by using antagonists of the purinergic receptors P2X(1), P2Y(1), and P2Y(12) (i.e. NF449, MRS2159, MRS2179, and cangrelor)...

..An adenosine A(1)-like receptor mediating relaxation and a P2X-like receptor mediating contraction is demonstrated at all stages...

..These results suggest that the Ca(2+) signaling to nucleus via the store-operated system including the ERs in the outer process is crucial for the cell cycle progression in the retinal neuroepithelium...

..Taken together, these data indicate that both metabotropic receptors and ionotropic receptors are present in rat Sertoli cells through which extracellular nucleotides can act...

..It should be noted that these Ca2+ signals and their modulation by Zn2+ could occur in the hippocampus in situ since both ATP and Zn2+ are rich in the hippocampus and could be released by excitatory stimulation...

..These results provide a molecular basis for calcium-induced bicarbonate secretion in pancreatic duct cells and highlight the importance of CFTR in epithelial bicarbonate secretion induced by various stimuli...

b>Purinergic receptors are important in the regulation of renal hemodynamics; therefore, this study sought to determine if such receptors influence macula densa cell function...

..This pathway might by mediated by the increasing expression of P2X(4)-receptors resulting in an increasing ATP-dependent membrane depolarization and activation of L-type Ca2+ channels...

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..that electrical field treatment of multicellular tumor spheroids results in ATP release, which concomitantly activates purinergic receptors, elicits a Ca(2+) wave spreading through the tumor spheroid tissue and stimulates tumor growth.

..These results support our hypothesis that adenine nucleotides are rapidly and locally converted into Ade on the membrane surface, resulting in the activation of A(2B) receptors...

..Therefore, ATP stimulates glybenclamide-sensitive Cl(-) secretion, and this action is partly mediated by PKA-dependent pathway via P1-like receptor...

..The length of the time window and the magnitude of the prolongation of neural activity both depend on the strength of the feedforward ADP-mediated inhibition of the ecto-5'-nucleotidase...

..Experiments using ATP, UTP and related compounds showed the involvement of P2Y2 and P2Y4 purinoceptors in the expression induced by ATP...

..05). The results suggest that activation of vascular and glomerular purinergic P2 receptors may contribute to the mesangial cell transformation, renal inflammation, and vascular hypertrophy observed in ANG II-dependent hypertension...

..Combined with our previous study, our data also provide further evidence that the sensitization of primary afferent nociceptors is subject to sympathetic modulation by activation of P2X as well as alpha(1)-adrenergic receptors...

..It appears that the hyposmotically-activated and ATP-stimulated K(+) efflux pathways are separate entities. However, there may be a degree of 'crosstalk' between the two pathways...

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..The properties of purinergic transmission at astrocyte junctions may determine many of the characteristics of Ca2+ propagation in networks of these cells...

..This novel intracellular function of anandamide may precede its action at cannabinoid receptors, and might be relevant to its control over neurotransmitter release...

..For example, ATP may contribute to both the vasodilation and the inflammation associated with rosacea...

..The concentration dependence of I (ATP) can be fitted using a Hill equation, yielding an EC(50) of 56 microM. Results are consistent with the parallel activation of both P2X and P2Y receptors...

..These results indicate that glial cells contribute to neurovascular coupling and suggest that regulation of blood flow may involve both vasodilating and vasoconstricting components...

..Recently, purinergic receptors have been shown to exist on Schwann cells of axon varicosities in visceral smooth muscle where they are ..

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..The present study suggested that the extracellular ATP-purinoceptor system was responsible for the intercellular synchronization of Ca(2+) oscillation among cardiac myocytes...

We investigated purinergic receptors involved in ion transport regulation in the intact rabbit nasal airway epithelium...

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..Here we show that multiple subtypes of purinergic receptors are differentially expressed in olfactory receptor neurons and sustentacular support cells...

..Thus, ATP dependent linear increases in [Ca(2+)](c) did not give rise to a corresponding increase in CSN activities, contravening the normally expected increase in CSN activities following [Ca(2+)](c) rise...

..CONCLUSION: This study showed that P2Y2 and P2Y11 receptors were expressed in NHNE cells and that their agonists, UTP and ATPgammaS, act as secretogogues on mucin secretion via Ca2+-dependent pathways...

..These distinct mechanisms operate in synergy in various CNS structures and form the "purinergic regulatory complex" of the synaptic transmission...

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..Immunohistochemical localization of purinergic receptors confirms the presence of some subtypes of P2X, P2Y and A1 receptors on neuronal cell bodies and fibers ..

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..Activation of A(1) and/or A(2) receptors inhibit N- and P/Q-types VDCCs via G(i)-protein betagamma subunits. Activation of P2X purinoceptors facilitates Ca(2+) entry in NTS...

..of intercellular Ca2+ waves, which have been previously shown to involve release of ATP and activation of purinergic receptors. Cells transiently exposed to EGF also showed a sustained potentiation of the Ca2+ signaling response to ..

..We conclude that changes at the level of capacitative entry mechanisms rather than switching of receptor subtype or coupling to phospholipase C underlies pregnancy adaptation of UAEC at the level of Ca(2+)signaling...

..There is also some evidence to suggest the presence of receptors for UTP, i.e., pyrimidinoceptors, which depolarize SCG neurones...

..The dopamine release evoked by UTP requires external Ca2+ which may enter the cells through pathways sensitive to Zn2+ but insensitive to Cd2+ or nicardipine...

..In contrast,activation of ATP-receptors which are linked to PTX-insensitive G-protein(s) do not interact synergically with histamine H1-receptors...

..These results suggest that C6Bu-1 cells possess ecto-enzymes converting beta,gamma-MeATP to adenosine, and the locally accumulated adenosine in this mechanism efficiently stimulates A2B receptors in a manner resistant to exogenous ADA...

..6. The opposite response of ciliated ependymal cells to 5-HT and ATP provides a novel mechanism for their active involvement in central nervous system signalling...

..5. These studies reveal that the [3H]-NECA binding assay in combination with HAK2701 is successful in the characterization of P3LP, especially the membrane-bound form...

..These data show for the first time the expression of functional P2X7 receptors in a subpopulation of osteoblasts, activation of which can result in ATP-mediated apoptosis...

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..Inconsistencies in antagonist effects against nucleotides are probably due to this activation of two receptors. The presynaptic P2-purinoceptor is P2Y-like, as it is in the peripheral sympathetic nervous system...

..Furthermore, we conclude that in addition to the classical P2y-subtype, which is largely PPADS-resistant,the guinea-pig taenia coli may be endowed with a distinct relaxation-mediating P2-purinoceptor subtype which is sensitive to PPADS...

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..CGRP produces either indirect excitatory or direct inhibitory responses by stimulation of CGRP2 and CGRP1 receptors, respectively...

..These channels differ from the ATP-regulated potassium channels activated by cromakalim...

..Also, autoinhibitory prejunctional alpha2-adrenoceptors regulate the LCN excitatory pathway to cat colon circular muscle...

..of extracellular ATP and adenosine in immunoregulation have evolved in studies of individual molecules of purinergic receptors and of phosphorylation of extracellular domains of functionally important proteins...

..It is concluded that BAME cells express a nucleotide receptor linked to phospholipase C and phospholipase D, but that activation of phospholipase D is probably down-stream of phospholipase C...

..On the other hand, our results suggest that renal A,-adenosine receptors do not use stimulation of phosphoinositide breakdown as a transmembrane signalling system...

..Therefore, the functional nature of the responses mediated by P2X- and P2y-purinoceptors, relaxation and spasm respectively, are opposite to those seen in most smooth muscles...

..ATP also causes relaxation by a direct, probably P2Y-receptor-mediated effect on the smooth muscle. All motor effects of ATP are inhibited by the antagonist PPADS...

..The implications for physiology are discussed...

..NO probably acts through the guanylate cyclase, though a small fraction of its effect might be mediated by other mechanisms. Activators of the guanylate cyclase other than NO do not seem to participate in the NANC relaxation...

..These responses are mediated by so-called P2-purinergic receptors which are activated upon binding ATP and other nucleotides...

There has been increasing interest in a large family of very widely distributed purinergic receptors. We are attempting currently to express the cDNA of A2 and putative A1 adenosine receptor genes in COS cells...

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..The proposed experiments will provide new information on mechanisms of O2 induced pulmonary vasodilation, a critical step for survival of newborn. ..

..Na+ channels, yanilloid receptors (VRl) which are sensitive to capsaicin, ATP-sensitive purinergic receptors, fast activation R+ channels and acid sensitive cation channels (ASIC), (3) Chronic pathological conditions ..

..P2Y receptors at these early time points, it will establish the M¿ller cell as a cellular target and the purinergic receptors as a molecular target for developing novel intervention and prevention strategies to combat the widespread ..

..the hypothesis that in response to stimulation, taste cells release ATP which then activates ionotropic purinergic receptors (P2X2 and P2X3) on the gustatory nerve fibers...

..The characterization of an angiogenic phenotype of VVEC, including purinergic receptors and coupled signaling pathways, will provide unique targets for therapeutic strategies aimed at inhibiting ..

..The characterization of an angiogenic phenotype of VVEC, including purinergic receptors and coupled signaling pathways, will provide unique targets for therapeutic strategies aimed at inhibiting ..

..The characterization of an angiogenic phenotype of VVEC, including purinergic receptors and coupled signaling pathways, will provide unique targets for therapeutic strategies aimed at inhibiting ..

..the hypothesis that in response to stimulation, taste cells release ATP which then activates ionotropic purinergic receptors (P2X2 and P2X3) on the gustatory nerve fibers...

..Understanding the regulation of 5-HT may be a key to management of functional bowel disease associated with an excess or reduced number of enterochromaffin cells. ..

..This information should prove useful in the development of new biochemical and pharmacological tools with potential use in the treatment of coagulation-related diseases. ..

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The cardiac actions of adenosine and adenosine 5'-triphosphate (ATP) are mediated by purinergic receptors present on cardiac myocytes...

..It is anticipated that these studies will provide new insights into mechanisms of synaptic transmission in the gut which could lead to the development of new and effect drug treatments for motility disorders. ..

..We have recently described the presence of two mitochondrial P2Y-like purinergic receptors, mP2Yi-like and mP2Y2-like, that increase mitochondrial Ca2+ uptake in response to changes in cytosolic [..

..Four specific aims are proposed to test mechanisms by which purinergic receptors influence microglial production of neurotoxic/inflammatory mediators, focusing on purinergic receptor MAP ..

..Four specific aims are proposed to test mechanisms by which purinergic receptors influence microglial production of neurotoxic/inflammatory mediators, focusing on purinergic receptor MAP ..

..been show to be an extremely important autocrine and paracrine mediator in the bladder and signals through purinergic receptors on both the luminal surface and in suburothelial layers e.g. on afferent nerve fibers...

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ATP and ADP acting through P2-purinergic receptors are physiologically important extracellular signalling molecules in the cardiovascular system, in the central and peripheral nervous systems, and in many other tissues...

..influence of NO, ATP, and ADO on the hypoxia- and hypercapnia-challenged CB; (2) to locate dopaminegic and purinergic receptors in the CB, the carotid sinus nerve, and in cell bodies of the petrosal ganglion (PG) with RT-PCR and ..