Comparative effects of verapamil and D-600 on the contractile responses produced by neurotransmitters and depolarizing agents in the rat isolated seminal vesicle.
1. The comparative effects of verapamil 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 microM) and D-600 (9.5 microM), selectively, reduced the isometric contractions, greater reductions occurred in the KCl-induced contractions (control EC50 19 +/- 1.5 mM, in verapamil 58 +/- 1.3 mM, and in D-600 37 +/- 2.0 mM, means +/- SE, n = 8, P less than 0.001, less than 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.
Wali
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FA
Department of Physiology, London Hospital Medical College, Whitechapel, U.K.
Greenidge
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D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D005711:Gallopamil / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012669:Seminal Vesicles / Q000187:drug effects; D014700:Verapamil / Q000494:pharmacology*
D009467:Neuromuscular Depolarizing Agents; D018377:Neurotransmitter Agents; D010656:Phenylephrine; D005711:Gallopamil; D011189:Potassium Chloride; D002217:Carbachol; D014700:Verapamil; D003000:Clonidine; D000109:Acetylcholine; D009638:Norepinephrine