title: Comparison of the characteristics of the negative inotropic actions of dinitrophenol, rotenone, antimycin A and the intracellular calcium antagonist, propyl-methylenedioxyindene.
abstract: The characteristics of the reversal of the comparable negative inotropic actions of 10(-4) M propyl-methylenedioxyindene (an intracellular calcium antagonist), 3 X 10(-5) M dinitrophenol (an uncoupler of mitochondrial oxidative phosphorylation), 10(-6) M rotenone (a site I mitochondrial respiratory chain poison) and 3 X 10(-6) M antimycin A (a site II mitochondrial respiratory chain poison) were studied in the isolated, electrically-paced guinea-pig left atrium. The negative inotropic effect of propyl-methylenedioxyindene was more sensitive to reversal by 5 mM calcium and 10(-9)-10(-7) M isoproterenol than were the comparable negative inotropic effects of dinitrophenol, rotenone and antimycin A. These results indicate that the negative inotropic effect of propyl-methylenedioxyindene is not exerted through inhibition of mitochondrial electron transport nor through uncoupling of mitochondrial oxidative phosphorylation.
mesh_terms: D000818:Animals; D000968:Antimycin A / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003864:Depression, Chemical; D004140:Dinitrophenols / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007192:Indenes / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D012402:Rotenone / Q000494:pharmacology*
chemical_list: D002121:Calcium Channel Blockers; D004140:Dinitrophenols; D007192:Indenes; D012402:Rotenone; D000968:Antimycin A; C027983:2-n-propyl-3-dimethylamino-5,6-methylenedioxyindene; D007545:Isoproterenol