Urinary cyclic AMP excretion is increased in Macaca fascicularis and Macaca mulatta compared to humans.

Changes in parathyroid hormone and its second messenger cyclic AMP have been implicated in the pathogenesis of osteoporosis. Nonhuman primate models have been useful in the study of osteoporosis, but the physiology of mineral metabolism in certain species is different than in humans. We investigated parameters of mineral metabolism in 15 normal adult female cynomolgus and 14 normal adult female rhesus monkeys. In both species, urinary cyclic AMP was increased compared with humans, and the nephrogenous cyclic AMP in the cynomolgus monkeys was also elevated. Despite this, there was no evidence for hyperparathyroidism in either species as evaluated by serum or plasma phosphorus and midregion-specific and/or aminoterminal-specific immunoreactive parathyroid hormone. Given the increasing use of nonhuman primates in the study of osteoporosis, understanding basic changes in mineral metabolism is important before pathologic effects of bone loss can be understood.