Autoradiographic studies on the effect of allopurinol on 14C-hypoxanthine metabolism in the squirrel monkey.

The Effect of orally given allopurinol in the distribution of intravenously administered 14C-hypoxanthine radioactivity was studied in squirrel monkeys 8 hr after administration of the label by the whole body autoradiography. Although the distribution of radioactivity in the normal and allopurinol-treated animals was essentially similar to each other, more intense radioactivity was noted in the latter monkey; salvage of 14C-hypoxanthine was enhanced. Similarly to our previous observation in mice, significant radioactivity in monkeys was seen in tissues undergoing rapid nucleic acid synthesis except for slight species differences in some organs. 14C-Allantoin alone as the urinary metabolite of the hypoxanthine in the normal monkey whereas significant amounts of 14C-hypoxanthine and 14C-xanthine as well were detected in the urine of the drug-treated animal.