Some Observations on Effect of Gamma Radiation on the Biochemistry of the Rat Thymus.

Abstract

Negligible changes were observed in the activities of succinic dehydrogenase, malic dehydrogenase, cytochrome oxidase, and adenosine triphosphatase in a thymus homogenate prepared from a rat exposed to 800 r of gamma radiation; however, pronounced diminution both in concentration and in P32 incorporation of thymus DNA, and to a lesser extent RNA, were evident 3 hours after exposure of the rat, and became progressively greater during a 96-hour post-irradiation interval. The capacity of a thymus homogenate to esterify inorganic phosphate was appreciably diminished in the irradiated rat. It is suggested that the diminished respiration observed in slices of thymus from irradiated rats is not a primary radiation effect, since comparable changes do not occur in the activity of individual respiratory enzymes studied here.