KCl-depolarization potentiates the Ca2+ sensitization by endothelin-1 in canine coronary artery.
In Ca(2+)-free solution containing endothelin-1 (ET-1), depolarization by high KCl increased the force of contraction without any changes in intracellular calcium concentration ([Ca2+]i) in canine coronary artery. The [Ca2+]i-force relationships were examined in the absence or presence of ET-1 in 5 or 90 mM KCl. The relation curve in the presence of ET-1 in 90 mM KCl-PSS was shifted to the left and upward compared with that in 5 mM KCl. These results suggest that KCl-depolarization potentiates the Ca2+ sensitization by ET-1.
Okada
Y
Y
Department of Pharmacology, Tohoku University School of Medicine, Sendai, Japan.
Yanagisawa
T
T
Taira
N
N
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects; D004285:Dogs; D004357:Drug Synergism; D016232:Endothelins / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects*; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology*
D016232:Endothelins; D009467:Neuromuscular Depolarizing Agents; D011189:Potassium Chloride; D002118:Calcium