Naloxone modifies the inotropic decrease induced by halothane on isolated left atria.
1. The present study evaluates the interaction between naloxone and halothane on the left atria. 2. Halothane produced significant decrease in auricular inotropism at concentrations ranging from 0.3 to 2.5 v/v%. 3. Naloxone modified the concentration response curve to halothane. The antagonism between both drugs is consistent with a competitive antagonism since the curve obtained had a slope which did not differ significantly from -1. 4. These results suggest that the negative inotropic effects induced by halothane could be mediated by opioid receptors.
Laorden
M L
ML
Department of Physiology and Pharmacology, School of Medicine, Murcia, Spain.
Carceles
M D
MD
Miralles
F S
FS
Hernandez
J
J
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D004558:Electric Stimulation; D005260:Female; D006221:Halothane / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D009270:Naloxone; D006221:Halothane