Changes in pre- and postoperative serum leptin concentrations in dogs with gallbladder mucocele and cholelithiasis

BACKGROUND: Leptin has been shown to have various physiological and pathological roles in the canine gallbladder. In this study, we performed pre- and postoperative short-term follow-up analyses to confirm changes in serum leptin levels before and after cholecystectomy due to gallbladder mucocele (GBM) or cholelithiasis in dogs. RESULTS: Twenty-six cholecystectomized dogs (GBM: n = 14; cholelithiasis: n = 12) for prophylactic or clinical symptom relief were enrolled in the present study. Dogs were subgrouped according to clinical symptoms and prognosis after surgery as follows: 1) asymptomatic group (n = 13), 2) recovery group (n = 8), and 3) death group (n = 5). Liver enzymes, total bilirubin, lipid profiles, and leptin concentrations were determined from sera on the pre-operative day and at 1, 3, and 7 days postoperation. Serum leptin concentrations were gradually but significantly decreased in the asymptomatic group (p = 0.008, 0.004, and 0.004 on days 1, 3, and 7, respectively, compared with that before surgery) and the recovery group (p = 0.048 and 0.048 on days 3 and 7, respectively, compared with that before surgery). However, in the death group, leptin concentrations did not differ significantly over time (p = 0.564). Additionally, serum leptin levels in the recovery group (p = 0.006) and death group (p = 0.021) were significantly higher than those in the asymptomatic group. Liver enzymes and total bilirubin (T-Bil) were significantly decreased only in the recovery group, particularly on day 7. In the asymptomatic group, liver enzymes and T-Bil were not changed significantly over time, and in the death group, only T-Bil was significantly decreased on day 7. Total cholesterol and triglyceride levels were not significantly decreased over time in all groups. CONCLUSIONS: These results indicate that leptin is a potential biomarker reflecting the severity and prognosis of GBM and cholelithiasis both before and after cholecystectomy in dogs.