Anti-shock effect of ACTH-(1-24) in rats: comparison between intracerebroventricular and intravenous route of administration.

In an experimental model of hypovolemic shock in rats, produced by withdrawing about 50% of the estimated total blood volume, and causing 100% deaths within 30 min, ACTH-(1-24) dose-dependently improved arterial and pulse pressure and increased survival rate. The intracerebroventricular (i.c.v.) route of administration was more effective than the intravenous (i.v.) route: at the dose of 24 micrograms/kg, 45% and 91% of rats were still surviving 2 hr after i.v. and i.c.v. treatment, respectively. At higher doses of ACTH-(1-24), the survival rate rose to 100% regardless of the route of administration, but arterial pressure increased more after i.c.v. than after i.v. injection. These data suggest that the CNS plays an important role in the anti-shock effect of ACTH.