Ca2+ influx in spontaneously hypertensive rats is sensitive to calcium antagonists.
Upon perfusion with a solution containing Ca2+, after Ca2+-free perfusion, aortic rings from spontaneously hypertensive rats (SHR) responded with a contraction. The contraction was usually transient. When verapamil or nifedipine were added prior to and during Ca2+ repletion, the force developed was reduced to 25% of that of uninhibited contraction. Aortas from normotensive rats did not show comparable properties. These findings demonstrate that calcium influx in aortic smooth muscle of SHR occurs mainly via voltage-dependent calcium channels.
D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D006973:Hypertension / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology
D002121:Calcium Channel Blockers; D014700:Verapamil; D009543:Nifedipine; D002118:Calcium