Actions of abscisic acid and the analogue SD217595 on calcium mediated activity of rat vas deferens smooth muscle.
1. K(+)-induced and Ca(2+)-induced contractures of rat prostatic and epididymal vas deferens smooth muscle were used to screen ABA and its analogue SD217595 for Ca2+ modulatory activity. 2. The Ca2+ agonist BAY K8644 significantly enhanced Ca(2+)-induced contractures while the Ca2+ entry blocker nifedipine strongly inhibited such contractures in both types of vas deferens preparation over the whole Ca2+ concentration range employed. 3. At 10(-7) mol 1(-1) ABA had no significant effect on K(+)-induced or Ca(2+)-induced contractures nor did it change the phasic/tonic force ratio in the preparations. 4. The ABA analogue SD217595 strongly inhibited Ca(2+)-induced contractures over the whole Ca2+ concentration range employed in both prostatic and epididymal vas deferens. 5. It is concluded that ABA is without significant Ca2+ modulatory activity in this smooth muscle preparation but the ABA analogue SD217595 possesses strong Ca2+ entry blocking ability.
Masters
A K
AK
Division of Biological Sciences, I.E.B.S., Lancaster University, England.
Huddart
H
H
Hetherington
A M
AM
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000040:Abscisic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014649:Vas Deferens / Q000187:drug effects
D011760:Pyrrolidinones; C089856:SD 217595; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000040:Abscisic Acid; D009543:Nifedipine; D011188:Potassium; D002118:Calcium