Establishment and Evaluation of a Rat Model of lipopolysaccharide-high-fat diet Induced Sarcopenia

Abstract

Abstract Objective To establish and evaluate a rat sarcopenia model. Methods We divided 10-month-old male Sprague–Dawley (SD) rats into adult control (AC) and lipopolysaccharide-high-fat diet (LPS-HFD) groups, in which LPS-HFD groups included a low-dose (150 µg/kg) lipopolysaccharide–high-fat diet (LD-LPS-HFD) and a high-dose (200 µg/kg) lipopolysaccharide–high-fat diet (HD-LPS-HFD) group. AC group rats were intraperitoneally injected with 0.9% physiological saline solution and fed ordinary feed; while LPS-HFD groups were intraperitoneally injected with LPS twice a week and had a high-fat diet for 8 weeks. Sarcopenia index (SI), relative grip strength, hematoxylin & eosin staining, Sirius red staining, western blotting, and enzyme-linked immunosorbent assay verified sarcopenia. Results SI values decreased in LPS-HFD groups and the differences were more than twice the standard deviation of the AC group. Regard to relative grip strength, only the difference in HD-LPS-HFD group was more than twice the standard deviation of the AC group. Cross-sectional areas and fiber diameters of LPS-HFD groups decreased, but were lower in the HD-LPS-HFD group than the LD-LPS-HFD group. MuRF1, FbX32, and p53 in LPS-HFD groups, and p21, IL-6, and TNF-α in the HD-LPS-HFD group increased, but were higher in the HD-LPS-HFD group than the LD-LPS-HFD group. Conclusion Sarcopenia is induced by peritoneal injection of LPS (200 µg/kg) and a high-fat diet for 8 weeks in 10-month SD male rats. This model is suitable to study the prevention and treatment of sarcopenia and its molecular mechanisms.