Participation of the nervous system in the adrenal cortical response to neurogenic stress

The response to immobilization stress has been studied in intact, hypophysectomized and hemidecorticated (bearing removal of the left cortical hemisphere) male rats. Blood and adrenal corticosterone content was measured fluorimetrically in these animals, killed at different intervals after the beginning of the stress. In intact animals, a monophasic curve, stabilized after 10 minutes, was obtained in blood, and a biphasic response occurred in the adrenal gland, with similar peaks at 5 and 30 minutes. In hypophysectomized animals a decrease of adrenal corticosterone, parallel to a blood increase, was found during the first 10 minutes. After 15 minutes the elevation was simultaneous in blood and adrenal glands. In hemidecorticated animals no difference was found between the homo and heterolateral glands to the ablation, but the adrenal basal level was higher than that in intact animals. The gas-liquid chromatographic study has permitted observation of changes in the relative concentrations of the different corticosteroids in the above mentioned groups.