Species variations among primates in responses to drugs which alter the renal excretion of uric acid.

The effects of salicylate, probenecid (Benemid) and pyrazinoate on uric acid excretion were determined in clearance experiments in the chimpanzee and Cebus monkey (C. albifrons and C. apella). The results were correlated with data from these species in the literature and where possible to analogous data in man. With salicylate, the rank order of responsiveness in terms of uricosuric action was chimpanzee greater than man greater than C. albifrons = C. apella. This was true when comparisons were made on the bases of drug concentration in plasma or the rate of drug excretion per milliliter of glomerular filtrate. A similar rank order was obtained with probenecid except that C. albifrons was slightly more responsive than C. apella. The latter comparisons were on the basis of plasma concentration of drug. The chimpanzee is more susceptible to the uricosuric action of pyrazinoate than is C. apella. With salicylate and pyrazinoate, there was urate retention at levels lower than those required for a uricosuric effect. The results suggest that in comparison with man, the chimpanzee is a hyperresponder to uricosuric drugs and Cebus monkeys are hyporesponders. Therefore, these findings limit extensions of quantitative results from one species to another.