The Effect of Whole-Body X-Irradiation on the Distribution of Acid Deoxyribonuclease and β-Galactosidase in Subcellular Fractions of Rat Spleen

Publisher Website
Google Scholar
Abstract
The distribution of acid deoxyribonuclease (DNase) activity in spleen subcellular fractions of rats given 70o r of whole-body X-irradiation was determined 16 and 64 hours post-irradiation and compared to tnat in pair-fed controls. In the controls, the distribution in nuclei, mitochondria, microsomes, and supernatant fraction was 25.8%, 30.69%, 10.7%, and 32.5%, respectively. Sixteen hours after irradiation this had changed to 15.9%, 26.9% , 13.1%, and 44.2%. There was no further significant change at 64 hours. Considerable increases in specific acid DNase activity were measured in all fractions 16 hours post irradiation; smaller changes were observed at 64 hours. At 16 hours postirradiation, a small net increase (14.5%) in total spleen DNase activity as compared to that in controls was seen. This increase might be caused by either increased enzyme syntnesis or increased susceptibility of spleen lysosomes from irradiated animals to breakage during isolation and assay. In spleen control animals, 67% of the [beta]-galactosidase activity was found in the supernatant fraction, and 700 r of whole-body X-irradia-tion did not significantly alter the distribution of this enzyme in subcellular fractions at either 16 or 64 hours postirradiation.