title: The effect of diltiazem on noradrenaline release.
abstract: The effects of diltiazem in rat tail arteries and guinea-pig vasa deferentia have been investigated. Superfusion of the rat tail artery with diltiazem (10(-6) - 10(-4) M) resulted in a dose-related increase in 3H-overflow (P less than 0.001) both in Wistar Kyoto (WKY) and in spontaneously hypertensive (SHR) rats. Release of 3H by transmural stimulation (1 Hz, 2 ms, 10 V) was also much greater in vessels perfused with diltiazem; this effect was dose-dependent. Diltiazem did not significantly alter the proportion of noradrenaline and its metabolites in 3H-overflow, as analysed by column chromatography. In the vasa deferentia of guinea-pigs, diltiazem (10(-9) - 10(-5) M) increased spontaneous 3H-release. The results indicate that diltiazem acts on sympathetic nerves and causes the release of noradrenaline.
mesh_terms: D000818:Animals; D001158:Arteries / Q000294:innervation / Q000378:metabolism; D001552:Benzazepines / Q000494:pharmacology*; D004110:Diltiazem / Q000494:pharmacology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D013623:Tail / Q000098:blood supply; D014316:Tritium; D014649:Vas Deferens / Q000294:innervation / Q000378:metabolism
chemical_list: D001552:Benzazepines; D014316:Tritium; D004110:Diltiazem; D009638:Norepinephrine