Activity of glibenclamide-sensitive K+ channels under unstimulated conditions in smooth muscle cells of pig proximal urethra
Teramoto, N., Creed, K.E. and Brading, A.F. (1997) Activity of glibenclamide-sensitive K+ channels under unstimulated conditions in smooth muscle cells of pig proximal urethra. Naunyn-Schmiedeberg's Archives of Pharmacology, 356 (3). pp. 418-424.
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The membrane potential in pig proximal urethra was examined by use of the microelectrode technique. In cells 1-2 cm from the bladder neck the membrane potential was quiescent, with a value of -37.2±2.5 mV (n = 16). In some cells small spontaneous de- and hyperpolarizations were seen. Glibenclamide (1 μM) caused a small but significant depolarization in tissue strips (12±3 mV, n = 3) and also in dispersed cells using whole-cell patch electrodes (13±3 mV, n = 5). In the conventional whole-cell voltage-clamp configuration, glibenclamide reduced the noise level of the basal membrane current at -50 mV and inhibited the mem- brane current in symmetrical 140 mM K+ conditions. In cell-attached patches, brief openings of a glibenclamide-sensitive 43 pS K+ channel (K(GS)-43 pS) were seen even under unstimulated conditions and greater activation occurred in the same membrane patch on subsequent application of 100 μM levcromakalim. These results provide direct evidence that glibenclamide-sensitive K+ channels may play a role in maintaining the resting membrane potential of pig proximal urethra under unstimulated conditions.
|Publication Type:||Journal Article|
|Murdoch Affiliation:||School of Veterinary and Biomedical Sciences|
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