Effect of whole-body X-irradiation on the adrenal medulla and the hormones adrenaline and noradrenaline

¹ Memorial Research Center and Hospital, Knoxville, Tennessee

The purpose of these experiments was to determine the effect of x-irradiation on the adrenaline and noradrenaline content of the adrenal gland and on the biosynthesis of these hormones. Rats, rabbits and cats were irradiated. Adrenal glands were removed at various times post irradiation and assayed for adrenaline and noradrenaline. Further, irradiated adrenal slices were incubated with labeled tyrosine and labeled methionine and the effect of irradiation upon the biosynthesis of adrenaline and noradrenaline determined. The results of these experiments show that x-irradiation (1770 r) does not decrease the biosynthesis of adrenaline and noradrenaline. However, whole-body irradiation does cause the adrenaline and noradrenaline content of the adrenal gland to decline; the adrenal gland content ultimately returns to normal. In view of these findings, it would seem that x-irradiation represents another form of ‘stress’ in which the physiological demand for adrenaline and noradrenaline is so great that the adrenal gland is partially or completely depleted of its adrenaline-noradrenaline storage.