Effects of dehydroepiandrosterone sulfate on the conversion of corticosterone into 11-dehydrocorticosterone in stress: a regulatory scheme.

In male rats, repeated but not single exposures to stress increased the conversion of corticosterone (CS) to 11-dehydrocorticosterone (11-DHCS), particularly on the background of administration of dehydroepiandrosterone sulfate (DHEAS). Naltrexone given 20 min before DHEAS at a dose of 0.1 mg/kg, at which it selectively blocks mu opioid receptors, prevented this effect of DHEAS, which is evidence that it is mediated by mu opioid receptors. This action of DHEAS involved endogenous ACTH and was thus mediated by central regulatory mechanisms. Our results, along with published data, lead to the first proposed scheme for the physiological regulation of the interconversion of CS and 11-DHCS in conditions of repeated stress with the involvement of DHEAS and mu opioid receptors.