Effects of caffeine and ryanodine on KCa in porcine coronary artery smooth muscle cells / 中国病理生理杂志
Chinese Journal of Pathophysiology
;
(12)1986.
Article
in Chinese
| WPRIM
| ID: wpr-533371
ABSTRACT
AIM:
To study the effect of caffeine on the large conductance calcium activated potassium (KCa) channels by patch-clamp technique on smooth muscle cells enzymatically isolated from the porcine coronary artery (PCASMC),and to investigate the effect of ryanodine on KCa being activated by caffeine.METHODS:
Using the single channel patch-clamp technique,single PCASMC was isolated by collagenase,the activity of single KCa channel was recorded in porcine coronary artery smooth muscle cells.RESULTS:
Caffeine (0.1-10 mmol/L) enhanced the open probability (Po) of KCa channels in a dose-dependent manner in the intracellular side of inside-out patches and its effect was almost completely abolished by washout. Caffeine decreased the mean close time markedly,but had no effect on the amplitude of KCa channels. However,ryanodine (10-40 ?mol/L) decreased Po of KCa channels activated by caffeine in a dose-dependent manner in cell-attached patches. The mean open time also decreased.CONCLUSION:
Caffeine directly activates KCa channels of porcine coronary artery smooth muscle cells in inside-out patches,the activity of single KCa channel is inhibited by ryanodine indirectly in cell-attached patches.
Full text:
Available
Index:
WPRIM (Western Pacific)
Language:
Chinese
Journal:
Chinese Journal of Pathophysiology
Year:
1986
Type:
Article
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