Effects of hexoestrol on the contractility of the isolated, blood-perfused canine papillary muscle and of the guinea-pig ileum.
The effects of hexoestrol were studied on the blood flow and the tension development of the isolated, blood-perfused papillary muscle of the dog, as well as on the contractions of the guinea-pig ileum induced by acetylcholine, histamine or BaCl2. Hexoestrol caused an increase in coronary blood flow and a negative inotropic effect in a dose-dependent manner. High doses of hexoestrol produced a loss of contractility of the papillary muscle without significant alterations of the amplitude and shape of the electrical activity recorded extracellularly. Hexoestrol had a strong non-selective relaxant effect on the guinea-pig ileum and was 10-20 times more potent than papaverine in antagonizing contractions induced by the 3 agonists. These results indicate that hexoestrol probably acts by blocking certain steps in the process by which extracellular and/or superficially bound Ca ions move to the contractile machinery in cardiac and in smooth muscle cells. Thus, it may bear some resemblance to the so-called calcium antagonists.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001464:Barium / Q000494:pharmacology; D003326:Coronary Circulation / Q000187:drug effects; D004155:Diphenhydramine / Q000494:pharmacology; D004285:Dogs; D005260:Female; D006589:Hexestrol / Q000494:pharmacology*; D006632:Histamine / Q000494:pharmacology; D007082:Ileum; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009200:Myocardial Contraction / Q000187:drug effects*; D010208:Papaverine / Q000494:pharmacology
D006589:Hexestrol; D001464:Barium; D001285:Atropine; D006632:Histamine; D004155:Diphenhydramine; D010208:Papaverine; D000109:Acetylcholine