Effect of corticosteroids on the secretion of the serum thymic factor and on the content of mast cell affinity lymphocytes in rats

: The level of thymus serum factor (TSF) was studied in the circulation of adrenalectomized rats and in the administration of corticosteroids. The effect of adrenocortical hormones on the receptor properties of thymocytes by the ability of mast cells to form mastolymphocytic rosettes (MLR) with thymocytes was also studied. The TSF content was shown to decrease to the level observed in thymectomized animals 40 h after administration of 125 mg/kg hydrocortisone. The MLR amount formed by thymocytes decreased significantly either. Adrenalectomy mas accompanied by an increase in the TSF content early after operation and at later time the MLR amount rose. Sham adrenalectomy resulted in a decrease in the TSF amount early after operation.