ABSTRACT
BACKGROUND: Comparative studies of kidney morphophysiology in nonhuman primates can help us investigate interspecies differences in growth and aging patterns. METHODS: We tested the effect of age and sex in renal morphophysiology in 21 Alouatta caraya and 21 Sapajus apella (age range = 0.5-26 years) by ultrasound, red blood cell (RBC) count, and kidney function tests. RESULTS: A. caraya had greater growth rate and absolute renal volume than S. apella, but the latter showed a greater relative renal volume and RBC count. There was a negative relationship between RBC and age, a positive relationship between creatinine and body mass, and an apparent negative relationship between creatinine and age only in S. apella. CONCLUSIONS: Our results indicate that A. caraya has a faster aging mechanism than S. apella, and the higher relative kidney volume in S. apella is suggestive of high metabolic demands in this species.
