EFFECT OF ADRENOCORTICAL STEROIDS AND ACTH ADMINISTRATION ON BARBITAL ANESTHESIA IN NORMAL MICE

¹ Department of Pharmacology and Endocrinological Laboratories, School of Medicine, Gunma University, Maebashi, Japan

The effects of administration of adrenocortical steroids and ACTH on the onset, duration and depth of barbital anesthesia and on the concentration of the drug in the brain at 3 hours after the injection were ascertained in normal mice. Further, the mechanism of action of ACTH on barbital concentration in the brain was investigated in adrenalectomized mice.

The induction time of barbital anesthesia was not changed by cortisone acetate, hydrocortisone acetate, substance S or DCA, but it was shortened by ACTH. The duration was shortened by cortisone acetate, hydrocortisone acetate or ACTH, while not affected by substance S or DCA. Depth of anesthesia at 3 hours after barbital injection was less in the cortisone acetate, the hydrocortisone acetate and the ACTH group than in the control, but unchanged by substance S and DCA. Barbital concentration in the brain was decreased by cortisone acetate, hydrocortisone acetate and ACTH, but not affected by substance S and DCA. Barbital concentration in the brain in adrenalectomized mice was not affected by ACTH.

From the above results it is considered that the shortening of the duration of barbital anesthesia by cortisone acetate, hydrocortisone acetate or ACTH might be due to the decrease of barbital concentration in the brain induced by these hormones.