Biomedical subjects
Publications and source records attributed to M V Ovsyukova.
In male rats exposed to repeated stress, the decrease in stress reactivity produced by subcutaneous injection of dehydroepiandrosterone sulfate (recorded by the decrease in stress-induced concentrations of corticosterone and adrenocorticotropic hormone in blood plasma) was observed 1-6 days postinjection and involved central regulatory mechanisms.
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.
Dehydroepiandrosterone sulfate prevented the increase in corticosterone level in rats induced by repeated exposure to stress. The mu-opioid receptor blocker naltrexone administered in a dose of 0.1 mg/kg 20 min before treatment with dehydroepiandrosterone sulfate abolished the effect of this agent. Dehydroepiandrosterone sulfate and naltrexone had no effect on rats after acute stress.
The relevance of the social contact test "Wall" for evaluation of sexual motivation of male mice was tested and confirmed. Motivation of C57BL/6J male mice with alternative social experience (winners and victims in 10 and 20 daily male-male confrontations) was evaluated. Elevated primary sexual interest was detected in aggressive animals after 10 confrontations, while in submissive animals this interest was decreased; however after 20 confrontations sexual motivation in both groups was characterized by rapid exhaustion and low basal level of testosterone. Hence, the sexual function of male mice is inhibited under conditions of long social conflicts irrespective of previous experience of victories or defeats in male-male confrontations.