Effects of anesthetic agents on serum parathyroid hormone and calcium concentrations in mice

OBJECTIVE: To determine the effects of three anesthetic regimens on serum calcium and parathyroid hormone (PTH) in mice. STUDY DESIGN: Prospective experimental study. ANIMALS: Twenty-seven, 12-week-old, FVB mice. METHODS: Mice were anesthetized with either isoflurane, a combination of ketamine plus xylazine (100 and 10 mg kg(-1), respectively) or ketamine alone (100 mg kg(-1)). Blood was collected before and after the induction of anesthesia. Serum calcium and PTH concentrations were measured and compared. RESULTS: Isoflurane or ketamine did not significantly alter either serum calcium or serum PTH concentrations. A combination of ketamine plus xylazine significantly increased serum PTH, but not serum calcium concentrations. CONCLUSIONS: A combination of ketamine and xylazine should be avoided prior to collection of blood for measurement of serum PTH concentrations. Isoflurane is suitable for this purpose.