Inhibitory action of human serum on the isoprenaline-induced chronotropic effect in cultured rat heart cells. Influence of sex and pregnancy.
Cultures of beating rat myocardial cells brought into contact with various human sera during 24 hours were infused with isoprenaline. The isoprenaline-induced positive chronotropic effect (IIPCE) was not found with all sera. IIPCE was present in all the male sera, but was absent in the cases of clinically beta-blocked pindolol treated men. IIPCE was present only in about 50% of the female sera, menopaused or not. IIPCE was absent in 95% of the sera of pregnant women in the late phase of pregnancy. This suggests the presence in female sera, especially during pregnancy, of a circulating factor capable of "in vitro" inhibition of isoprenaline-induced positive chronotropic effect.
D000328:Adult; D000818:Animals; D001769:Blood; D002478:Cells, Cultured; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D011247:Pregnancy; D051381:Rats; D012737:Sex Factors; D013268:Stimulation, Chemical
D007545:Isoproterenol