Noradrenaline and tyramine action on isolated atrial muscle of endotoxin-treated guinea-pigs.
1. Isolated left-atrial strips of guinea-pigs were driven electrically at a constant rate and log-concentration curves were determined for the positive inotropic effect of noradrenaline and tyramine.2. The atrial tissue from endotoxin-treated animals had a reduced sensitivity to noradrenaline and tyramine.3. After endotoxin, the sensitizing effect of cocaine on the response to noradrenaline was normal but accumulation of (3)H-noradrenaline in nerve terminals was markedly reduced.4. Atrial tissue of endotoxin-treated guinea-pigs responded normally to stretch.
D000818:Animals; D003042:Cocaine / Q000494:pharmacology; D004357:Drug Synergism; D004548:Elasticity; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology*; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000032:analysis; D009638:Norepinephrine / Q000032:analysis / Q000494:pharmacology*; D012772:Shock, Septic / Q000503:physiopathology*; D014316:Tritium; D014439:Tyramine / Q000494:pharmacology*
D014316:Tritium; D003042:Cocaine; D009638:Norepinephrine; D014439:Tyramine