THE ANESTHETIC ISOFLURANE DECREASES IONIZED CALCIUM AND INCREASES PARATHYROID-HORMONE AND OSTEOCALCIN IN CYNOMOLGUS MONKEYS

The effects of anesthetics on calcium metabolism in cynomolgus monkeys were studied. Eight adult female cynomolgus monkeys were used in a cr ossover design. Blood was collected from each of the monkeys at four t imepoints: (1) while conscious; (2) following induction of anesthesia with ketamine, ketamine and atropine, isoflurane, or no anesthetic; (3 ) at 30 min; and (4) 120 min thereafter. Four experiments were perform ed with al week washout period between sessions, such that each monkey received each treatment. Potassium was lower in anesthetized monkeys than in those that remained conscious. Cortisol, although high, did no t differ among anesthetic treatments. Ketamine and ketamine/atropine d id not consistently affect ionized calcium or parathyroid hormone (PTH ) concentrations. Isoflurane decreased ionized calcium (0.05 mmol/L), and increased PTH and osteocalcin twofold. The serum inorganic fluorid e concentration was higher in monkeys anesthetized with isoflurane tha n with ketamine/atropine, which may partially account for the decrease in ionized calcium with isoflurane, The increases in PTH and osteocal cin are presumably secondary to the decrease in ionized calcium. (C) 1 998 by Elsevier Science Inc. All rights reserved.