Ratio between the contents of 11-dehydrocorticosterone and corticosterone after acute and repeated stress: effect of dehydroepiandrosterone sulfate.

Acute stress was accompanied by reduction of 11-dehydrocorticosterone to corticosterone in male rats. The reverse reaction predominated during repeated stress and increased after administration of dehydroepiandrosterone sulfate. Treatment with mu-opioid receptor antagonist naltrexone in a dose of 0.1 mg/kg 20 min before administration of dehydroepiandrosterone sulfate abolished this effect.