Effects of converting enzyme inhibitors and the calcium antagonist nifedipine alone and in combination on precontracted isolated rabbit aortic rings.
The calcium antagonist nifedipine markedly relaxed intact rabbit aortic rings precontracted with low level potassium chloride while converting enzyme (CE) inhibitors, ramiprilat, enalaprilat, and captopril were only marginally effective. Either CE inhibitor combined with nifedipine, however, significantly accentuated this relaxation. The CE inhibitors increased vascular cyclic GMP content while nifedipine was not active. Thus, inhibition of potassium chloride-induced calcium influx by nifedipine may unmask the vasorelaxant potential of CE inhibitors that in turn may result from local accumulation of endothelium-derived bradykinin.
Wiemer
G
G
Hoechst Aktiengesellschaft, Strategic Business Unit, Frankfurt/Main, Fed. Rep. of Germany.
Becker
R H
RH
Jablonka
B
B
Rosenkranz
G
G
Schölkens
B A
BA
Linz
W
W
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009543:Nifedipine / Q000008:administration & dosage / Q000494:pharmacology*; D009569:Nitric Oxide / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D014665:Vasodilator Agents / Q000494:pharmacology*
D000806:Angiotensin-Converting Enzyme Inhibitors; D014665:Vasodilator Agents; D009569:Nitric Oxide; D011189:Potassium Chloride; D006152:Cyclic GMP; D009543:Nifedipine