[Mechanisms of hexobarbital anesthesia potentiation by hydrocortisone]

The authors carried out studies on white rats of Wistar strain and investigated some of the mechanisms, metabolic and central, by means of which hydrocortisone affected hexobartital sleep. They established that hydrocortisone in dose of 25 and 50 mg, administered singly, together with hexobarbital or after a 30-minute interval, potentiated hexobarbital sleep significantly. The concentrations of hexobarbital in blood serum and in brain on the 30th minute after its administration were higher in the experimental animals, treated with hexobarbital in comparison with the controls of both sexes. The experiments with determination of the activity of liver microsomal hexobarbital enzymic system showed convincingly a considerable inhibition of enzymic activity (with 53%) of hydrocortisone after 20 minutes after its application in vivo. Subthreshold sreep dose of hexobarbital, determined by the method of Lewy, was lowered than that of the experimental group and higher in the control rats. Hexobarbital concentrations in blood serum and in brain at the moment of waking were lower in experimental animals, treated with hydrocortisone, and higher in the control animals. The obtained results gave foundations to the authors to assume that metabolic and central nervous mechanisms participated in potentiation of hexobarbital sleep.