Hypocalcemic effect of acetylsalicylic acid in rats

Oral administration of acetylsalicylic acid (ASA) at a dose of 200 mg/kg produced a decrease in both total plasma calcium and plasma ionic calcium levels in rats. The percent changes from controls in both total and ionic calcium were similar, being approximately 13% at 3 hr after the administration. A significant (p less than 0.01) decrease in plasma calcium level was also observed at 4 hr after oral administration of salicylic acid at a dose level of 177 mg/kg. However, oral administration of other non-steroidal anti-inflammatory agents such as indomethacin failed to decrease plasma calcium levels in rats. The hypocalcemic effect of ASA was recognized in parathyroidectomized rats, but neither in thyroparathyroidectomized nor in thyroidectomized rats. Therefore, the data suggested that the action of ASA might be mediated by stimulation of calcitonin release, but not by inhibition of prostaglandin biosynthesis.