The effect of thalidomide on visceral fat pad mass and triglyceride concentration of the skeletal muscles in rats

Background: Body fats, especially both of abdominal fat pad mass and skeletal muscle fat content, are inversely related to insulin action. Therefore, methods for decreasing visceral fat mass and muscle triglyceride content may be helpful for the prevention of insulin resistance. Methods: Thalidomide, used for its anti-angiogenic and anti-inflammatory properties, was administered to rats for 4 weeks. A 10% solution of thalidomide in dimethyl sulfoxide was injected daily into the peritoneal cavity as much as 100 mg/kg of body weight. Results: The total visceral fat pad mass in the thalidomide-treated group was 11% lower than in the control group. The size of adipocytes of the epididymal fat pad mass in the thalidomide-treated group was smaller than in the control group. The intraperitoneal thalidomide treatment increased triglyceride concentrations by 16% in the red muscle, but not in the white muscle. Conclusion: The results suggested that intraperitoneal thalidomide treatment inhibited abdominal fat accumulation, and that the free fatty acids in the blood were preferentially accumulated in the red muscle rather than in the white muscle.