Assessment of Effects of Thyrotoxicosis on Gallstone Formation in Rabbits

Abstract

Aim: The etiopathogenesis of gallstone formation is well known, but only a few studies have investigated the effects of thyrotoxicosis on gallstone formation. In this study, we investigated the contribution of thyrotoxicosis to gallstone formation in rabbits. Methods: Forty-four New Zealand rabbits were used. The rabbits were divided into six groups, with each group receiving a different diet. At the end of seven weeks, all rabbits were sacrificed, blood was collected for analysis, and cholecystectomy was performed. Results: Serum levels of both free triiodothyronine (FT3) and thyroxine (FT4) were significantly higher in rabbits receiving thyroid hormone (p<0.001). The bile cholesterol saturation index (CSI) in the group receiving only thyroxine hormone was statistically higher than in the control group (p=0.014). The rabbit group receiving a lithogenic diet and thyroxine hormone had significantly higher myeloperoxidase activities and fibrinogen levels, but lower bile acid levels compared to controls (p<0.001). Focal leukocyte infiltration was noted in rabbits receiving thyroxine hormone, but no significant differences were found in bile calcium levels between the groups (p>0.05). Conclusions: Thyrotoxicosis promotes an increase in gallstone formation risk as a result of an increased bile CSI and gallbladder mucosal inflammation.