Effects of calcium antagonists on release of 3H-norepinephrine in rabbit aorta

摘要: Abstract Effects of several organic Ca antagonists and putative calmodulin on the release 3H-norepinephrine from rabbit aorta were examined. 65.4mM K solution increased 3H-efflux previously loaded with 3H-norepinephrine, increment was inhibited by removing in medium. Verapamil, D600, N-(6-aminohexyl)-5-chioro-l-naphthalenesulphonamide (W-7), N2-dansyl-L-arginine-4-t-butyIpiperidine amide (Tl 233), concentration 10-5M, did not inhibit K-induced increase 3H-efflux. Verapamil rather potentiated efflux. High (2 X 10-4M) verapamil W-7 The dependent external Ca. K, added presence 2 10-4M or W-7, produce further diltiazem, prenylamine Tl 233, 10-4M, also From these results, it is suggested that adrenergic nerve terminals are relatively insensitive to inhibitory effects high inhibitors themselves norepinephrine a mechanism independent