Effectiveness of ethylketocyclazocine in hemorrhagic shock.

The protective effect exerted by opiate antagonists in hemorrhagic shock appears to involve blockade of endogenous opioid substances at opiate receptors. The existence of several types of opiate receptors has been proposed. Previous work has shown that mu and delta opiate receptors may be involved in the shock process, but that k receptors appear not to be critically involved in the pathogenesis of shock. Administration of the potent k receptor agonist ethylketocyclazocine to hemorrhaged cats resulted in significant improvement in final mean arterial blood pressure and significant improvement in final plasma MDF activities compared to hemorrhaged cats given only vehicle. These data indicate that k receptor activation does not exacerbate the shock state, thus supporting the hypothesis that k receptors are not involved in the development of circulatory shock. Ethylketocyclazocine may act as an antagonist at the epsilon opiate receptor, indicating possible involvement of this receptor type in the pathogenesis of circulatory shock.