{"title":"INOTROPIC EFFECTS OF OUABAIN ON RABBIT LEFT ATRIA IN PRESENCE OF BETA-ADRENERGIC BLOCKING DRUGS.","authors":"J V LEVY, V RICHARDS","doi":"10.3181/00379727-119-30158","DOIUrl":null,"url":null,"abstract":"Summary The positive inotropic effects of ouabain on electrically driven rabbit left atrial preparations was studied in the presence of 3 drugs known to be potent and specific beta-adrenergic receptor antagonists (pronethalol, propranolol and MJ-1999). Ouabain alone (6.9 × 10-7 M) produced a highly significant increase in contraction force compared to untreated controls. Pronethalol (3.76 × 10-6 M) and propranolol (1.35 × 10-6 M) were found to produce significant decreases in contraction force. The methanesulfonanilide substituted isopropylphenylethylamine (MJ-1999) had no significant effects on contraction force in a concentration of 1.3 × 10-5 M. Administering ouabain after pretreatment with and in the presence of either pronethalol, propranolol, or MJ-1999 failed to modify significantly the normal positive inotropic effect of the glycoside. Therefore, no evidence was found to indicate that beta-adrenergic receptor blockade could prevent the positive inotropic effect of ouabain on isolated rabbit left atria.","PeriodicalId":20675,"journal":{"name":"Proceedings of the Society for Experimental Biology and Medicine","volume":" ","pages":"278-81"},"PeriodicalIF":0.0000,"publicationDate":"1965-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3181/00379727-119-30158","citationCount":"18","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the Society for Experimental Biology and Medicine","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3181/00379727-119-30158","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 18
Abstract
Summary The positive inotropic effects of ouabain on electrically driven rabbit left atrial preparations was studied in the presence of 3 drugs known to be potent and specific beta-adrenergic receptor antagonists (pronethalol, propranolol and MJ-1999). Ouabain alone (6.9 × 10-7 M) produced a highly significant increase in contraction force compared to untreated controls. Pronethalol (3.76 × 10-6 M) and propranolol (1.35 × 10-6 M) were found to produce significant decreases in contraction force. The methanesulfonanilide substituted isopropylphenylethylamine (MJ-1999) had no significant effects on contraction force in a concentration of 1.3 × 10-5 M. Administering ouabain after pretreatment with and in the presence of either pronethalol, propranolol, or MJ-1999 failed to modify significantly the normal positive inotropic effect of the glycoside. Therefore, no evidence was found to indicate that beta-adrenergic receptor blockade could prevent the positive inotropic effect of ouabain on isolated rabbit left atria.