Serum free and phospholipid-bound choline decrease after surgery and methylprednisolone administration in dogs

Abstract

We designed this study to determine whether serum free and phospholipid-bound choline concentrations change after surgery or methylprednisolone treatment in dogs and rats. In dogs, serum free and phospholipid-bound choline concentrations were decreased by 29% and 17% immediately after abdominal-pelvic surgery under xylasine + ketamine anesthesia, respectively, and both remained low for 24 h. Serum cortisol was elevated after surgery. The elevation in serum cortisol was inversely correlated with the decreases in free (r = -0.737; P < 0.001) and phospholipid-bound (r = -0.771; P < 0.001) choline concentrations. After methyprednisolone administration (5-20 mg/kg) free and phospholipid-bound choline concentrations decreased in a dose- and time-dependent manner. In rats, either surgery or methylprednisolone failed to alter serum free choline concentrations while phospholipid-bound choline decreased after surgery. These data show that the decrease in serum choline after surgery results from the increase in circulating glucocorticoids.