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

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. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.