Angiographic evaluation of the coronary vasodilating effect of trapidil in anesthetized closed-chest dogs.
We studied the effect of trapidil on coronary diameters of anesthetized closed-chest dogs using coronary angiography. Trapidil 2 mg/kg i.v. significantly (p less than 0.01) increased the diameter of the proximal (1.96 +/- 0.08 mm), middle (1.29 +/- 0.05 mm), and distal (0.86 +/- 0.03 mm) coronary arteries by 4.2 +/- 1.0, 7.6 +/- 1.2, and 10.8 +/- 2.2%, respectively. Nitroglycerin 20 micrograms/kg i.v. significantly (p less than 0.01) increased the diameter of classes I, II, and III arteries by 4.0 +/- 0.7, 7.7 +/- 1.3, and 7.5 +/- 1.8%, respectively. Ergonovine (0.4 mg i.v.; n = 13) reduced (p less than 0.01) the diameter of all three classes of coronary arteries by 8.2 +/- 1.2, 9.0 +/- 1.0, and 13.3 +/- 1.9%. After pretreatment with ergonovine, trapidil (n = 8) relaxed the coronary arteries from -10.4 +/- 1.7 to -2.4 +/- 1.7% constriction (p less than 0.05). These results indicate that in dogs trapidil dilates coronary arteries in a fashion similar to nitroglycerin and reverses ergonovine-induced coronary vasoconstriction.
D000818:Animals; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000187:drug effects*; D004285:Dogs; D004874:Ergonovine / Q000494:pharmacology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology*; D014192:Trapidil / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
D011743:Pyrimidines; D014192:Trapidil; D005996:Nitroglycerin; D004874:Ergonovine