Effects of semotiadil fumarate, a novel Ca2+ antagonist, on cytosolic Ca2+ level and force of contraction in porcine coronary arteries.

摘要: Abstract 1. The mechanisms of action semotiadil fumarate, a novel Ca2+ antagonist, were examined by measuring the cytosolic level ([Ca2+]i) and force contraction in porcine coronary arteries, determining [3H]-pyrilamine binding to bovine cerebellar membranes. 2. Semotiadil or verapamil (0.1 1 microM) inhibited both high KCl-induced increases [Ca2+]i concentration-dependent manner. 3. Histamine (30 produced transient followed sustained force, which (1 10 microM). agents different that reduced maximum responses histamine, but not pD2 values, whereas did reduce values for responses. 4. Verapamil (10 microM), semotiadil, histamine-induced Ca(2+)-free solution. Neither nor affected induced caffeine. even at higher concentration displace specific 5. These results suggest inhibits KCl- contractions mainly blocking voltage-dependent L-type channels.