Effects of morphine on atrial preparations obtained from nonfailing and failing human hearts.
We have examined the effects of morphine in auricular myocardium from non-failing and failing human hearts. In both preparations morphine induced inhibition. These responses were not antagonized by naloxone. Comparison of mean IC30 values obtained in non-failing (3.9 (SEM 0.2) x 10(-8) mol litre-1) and failing (5010 (200) x 10(-8) mol litre-1) hearts indicated that the morphine concentration-response curves were significantly (P < 0.001) shifted to the right in preparations from failing hearts. In addition, a decrease in the maximal response was observed. These data indicate that opioid receptors are not involved in the cardiac effects induced by morphine and that there is a decrease in responses to morphine in the failing heart.
Llobel
F
F
Department of Anaesthesiology, University School of Medicine, Murcia, Spain.
Laorden
M L
ML
D000328:Adult; D000368:Aged; D016280:Atrial Function, Right / Q000187:drug effects*; D002303:Cardiac Output, Low / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000503:physiopathology; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*
D009292:Narcotic Antagonists; D009294:Narcotics; D009270:Naloxone; D009020:Morphine