[Hemodynamic effect of an opioid receptor antagonist diprenorphine in canine endotoxic shock]

The hemodynamic effect of diprenorphine (M5050) in canine endotoxic shock was studied. Mean arterial pressure, left ventricular pressure, left ventricular contractility (dp/dt max), stroke volume, and cardiac output in the endotoxin-shocked dogs were significantly improved by intravenous injection of naloxone (2 mg/kg) and intraventricular microinjection of diprenorphine (40 micrograms), but not by intravenous injection of diprenorphine. It was suggested that the site of action of diprenorphine might be in the central nervous system, and the endogenous opioid substances in the central nervous system may play a more important role in the pathogenesis of septic shock than does that in the peripheral system.