F. Llobel et Ml. Laorden, EFFECTS OF MORPHINE ON ATRIAL PREPARATIONS OBTAINED FROM NONFAILING AND FAILING HUMAN HEARTS, British Journal of Anaesthesia, 76(1), 1996, pp. 106-110
We have examined the effects of morphine in auricular myocardium from
non-failing and failing human hearts. In both preparations morphine in
duced inhibition. These responses were not antagonized by naloxone. Co
mparison 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 hearts indi
cated that the morphine concentration-response curves were significant
ly (P < 0.001) shifted to the right in preparations from failing heart
s. In addition, a decrease in the maximal response was observed. These
data indicate that opioid receptors are not involved in the cardiac e
ffects induced by morphine and that there is a decrease in responses t
o morphine in the failing heart.