Comparative effects of verapamil and D-600 on the contractile responses produced by neurotransmitters and depolarizing agents in the rat isolated seminal vesicle (original) (raw)

1989, General Pharmacology: The Vascular System

AImtract-1. The comparative effects of veraparnil and D-600, on isometric contractions produced by noradrenaline, acetylcholine, phenylephrine, clonidine, carbachol and high potassium, were studied in rat isolated seminal vesicle. 2. The aim was to see if verapamil and D-600 differed, in their selectivity, of blocking calcium, channels, and hence inhibition of isometric contractions produced in this preparation. 3. Verapamil (1 pM) and D-600 (9.5/zM), selectively, reduced the isometric contractions, greater reductions occurred in the KCl-induced contractions (control EC~ 19+ 1.5mM, in verapamil 58 + 1.3 mM, and in D-600 37 + 2.0 raM, means + SE, n = 8, P < 0.001, <0.01, respectively). 4. It was concluded that KCl-induced contractions were voltage-dependent, whereas noradrenaline operated via both voltage and receptor-mediated mechanisms. 5. The clinical relevance of these results was discussed, and it may help our current understanding of the pharmacological management of sexual dysfunction.