ACTH-induced reversal of hemorrhagic shock: further studies on the mechanism of action.

In a rat model of extremely severe hemorrhagic shock, invariably leading to death within 30 min, the i.v. bolus injection of ACTH-(1-24) at the dose of 160 micrograms/kg produced a dramatic and sustained reversal of the shock condition, with normalization of mean arterial pressure, pulse pressure and respiratory rate, and with survival of all rats at the end of the observation period (2 h). Such effect was neither prevented nor reduced by the bilateral anesthetization of carotid bodies, suggesting that chemoreceptors of these structures are of no relevance in the complex mechanism of the ACTH-induced reversal of hemorrhagic shock.