[The mechanism of the action of opiate receptor antagonists in acute shock-induced blood loss].

Experiments on 81 rabbits showed that intravenous infusion of naloxone and nalorphine in different periods of hemorrhagic shock promoted the death of animals. It is concluded that in hypoxia only the antagonistic activity of the drugs is manifested as total inactivation of the endogenous opioid system depriving it of its protective functions. Nalorphine infused after blood reinfusion exhibits agonistic activity and additional activation of the endogenous opioid system promotes the use of the biological reserves by the organism, which saves some of the animals from death or essentially prolongs the survival of the others. Infusion of naloxone after blood transfusion has no effect on the outcome.