Zou, H. and Ugur, M. and Drummond, R.M. and Singer, J.J. (2001) Coupling of a P2Z-like purinoceptor to a fatty acid-activated K+ channel in toad gastric smooth muscle cells. Journal of Physiology, 534 (1). pp. 59-70. ISSN 0022-3751Full text not available in this repository. (Request a copy from the Strathclyde author)
1. Extracellular application of ATP generates two whole-cell currents in toad gastric smooth muscle cells: an immediate inward non-selective cation current (due to the activation of a P2X or P2Z-like receptor) and a slowly developing outward K+ current. The inward non-selective cation current depends on the continuous presence of ATP while the outward K+ current can last for minutes after ATP application ceases. 2. In cell-attached patches, application of ATP to the extra-patch membrane can activate K+ channels in the patch indicating that a diffusible cellular messenger may be involved. The characteristics of these K+ channels are similar to those of a previously described fatty acid-activated K+ channel that is also a stretch-activated channel. 3. This whole-cell K+ current can be induced by ATP in the absence of extracellular Ca2+ (with EGTA present to chelate trace amounts). However, the current generated in the presence of extracellular Ca2+ is considerably larger. 4. The pharmacological profiles for the activation of the non-selective cation current and the K+ current are similar, suggesting that the same P2Z-like receptor could be mediating both responses. This type of plasma membrane receptor/channel-channel coupling by a process that does not appear to involve Ca2+ flow through the receptor/channel or a subsequent membrane potential change may be representative of a new class of signalling mechanisms.
|Keywords:||P(2Z) purinergic receptors, extracellular atp, phospholipase D, BAC1.2F5 macrophages, potassium channels, calcium, nucleotides, secretion, agonists, Pharmacy and materia medica, Physiology|
|Subjects:||Medicine > Pharmacy and materia medica|
|Department:||Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences|
|Depositing user:||Strathprints Administrator|
|Date Deposited:||15 Apr 2011 10:12|
|Last modified:||06 Jan 2017 06:18|