Increased Leptin and Leptin Receptor Expression in Dogs With Gallbladder Mucocele

Abstract

Background: Leptin and its receptor play a role in several disease processes such as pancreatitis and heart disease. However, their association with gallbladder mucocele (GBM) in dogs has not been reported.

Hypothesis/objectives: To evaluate differences in the expression of leptin and leptin receptor between dogs with and without GBM.

Animals: Twenty-five healthy dogs, including 9 laboratory beagle dogs, and 22 client-owned dogs with GBM.

Methods: Serum leptin concentration was determined in blood samples of all dogs by ELISA. Canine gallbladder samples were collected from 9 dogs with GBM that underwent surgery for therapeutic purposes and from 9 healthy laboratory beagle dogs as a normal control group. Samples were analyzed for leptin and leptin receptor mRNA by real-time polymerase chain reaction.

Results: Serum leptin concentration was significantly higher in dogs with GBM than in healthy dogs (medians of 7.03 and 2.18 ng/mL, respectively; P < .001). Patients with GBM that had undergone surgery had significantly higher serum leptin concentrations than those that had not (medians of 12.2 and 4.09 ng/mL, respectively; P = .001). However, no difference in serum leptin concentration was found between dogs with GBM with or without endocrinopathies. The mRNA expression levels of leptin and its receptor were significantly increased in the gallbladder tissues of dogs with GBM.

Conclusions and clinical importance: Dysregulation of leptin might be involved in the pathophysiology of GBM, and leptin concentrations might be associated with GBM severity.

Keywords: Canine; Gallbladder mucocele; Leptin; Leptin receptor.

Figure 1

Comparison of the circulating leptin concentration (A) between healthy dogs (n = 25) and dogs with gallbladder mucocele (GBM, n = 22) and (B) between nonoperated (n = 13) and operated (n = 9) patients among the dogs with GBM. The horizontal bars indicate the medians and ranges. *P < .05 between 2 groups.

Figure 2

Comparison of the relative mRNA expression levels of (A) leptin and (B) leptin receptor in healthy dogs (n = 9) and dogs with gallbladder mucocele (GBM, n = 9). The columns represent the mean value of each parameter, and the vertical error bars indicate the standard deviation. *P < .05 between groups.

Figure 3

Comparison of (A) the circulating leptin concentration among healthy dogs (n = 25) and dogs with gallbladder mucocele (GBM, n = 22) classified according to the presence of endocrinopathy. The relative mRNA expression levels of (B) leptin and (C) leptin receptor in dogs with GBM (n = 22) depending on the presence of endocrinopathy. The horizontal bars of (A) indicate the medians and ranges. In (B) and (C), the columns represent the mean value of each parameter, and the vertical error bars indicate the standard deviation. *P < .05 between groups.