Inhibition of neurotransmission by angiotensin I and II in rabbit isolated ear artery.
Angiotensin I and II inhibited the nerve stimulation-induced pressure changes in isolated, perfused rabbit ear artery with an IC50 of 3.07 and 0.36 nM, respectively. Neither angiotensin I nor angiotensin II affected the basal pressure or the pressure changes elicited by exogenously administered norepinephrine (NE). The potency of angiotensin I was unaltered by 10(-5) M captopril, indicating that conversion by angiotensin converting enzyme (ACE) was not necessary and did not take place. [Sar1,Val5,Ala8]angiotensin II (3 x 10(-8) M) antagonized the effect of angiotensin I. These findings could have implications regarding ACE inhibitor therapy and the pathophysiology of migraine.
Rónai
A Z
AZ
Department of Biochemistry, L. Eötvös University, Budapest, Hungary.
D000803:Angiotensin I / Q000494:pharmacology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001158:Arteries / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology; D004423:Ear / Q000098:blood supply; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D011817:Rabbits; D012039:Regional Blood Flow / Q000187:drug effects; D012504:Saralasin / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects*
D000804:Angiotensin II; D000803:Angiotensin I; D002216:Captopril; D012504:Saralasin