title: Histopathological changes in rat pancreas and skeletal muscle associated with high fat diet induced insulin resistance.
abstract: The effects of a high fat diet on the development of diabetes mellitus, insulin resistance and secretion have been widely investigated. We investigated the effects of a high fat diet on the pancreas and skeletal muscle of normal rats to explore diet-induced insulin resistance mechanisms. Forty-four male Wistar rats were divided into six groups: a control group fed standard chow, a group fed a 45% fat diet and a group fed a 60% fat diet for 3 weeks to measure acute effects; an additional three groups were fed the same diet regimens for 8 weeks to measure chronic effects. The morphological effects of the two high fat diets were examined by light microscopy. Insulin in pancreatic islets was detected using immunohistochemistry. The homeostasis model assessment of insulin resistance index and insulin staining intensity in islets increased significantly with acute administration of high fat diets, whereas staining intensity decreased with chronic administration of the 45% fat diet. Islet areas increased significantly with chronic administration. High fat diet administration led to islet degeneration, interlobular adipocyte accumulation and vacuolization in the pancreatic tissue, as well as degeneration and lipid droplet accumulation in the skeletal muscle tissue. Vacuolization in the pancreas and lipid droplets in skeletal muscle tissue increased significantly with chronic high fat diet administration. We suggest that the glucolipotoxic effects of high fat diet administration depend on the ratio of saturated to unsaturated fatty acid content in the diet and to the total fat content of the diet.
authors.affiliation: a Department of Histology and Embryology , Faculty of Medicine, Canakkale Onsekiz Mart University , Canakkale , Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Ickin Gulen
authors.affiliation: b Department of Histology and Embryology , Faculty of Medicine, Sanko University , Gaziantep , Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Guven Bagla
authors.affiliation: c Department of Medical Biochemistry , Faculty of Medicine, Balikesir University , Balikesir , Turkey.
authors.forename: O
authors.initials: O
authors.lastname: Yavuz
authors.affiliation: c Department of Medical Biochemistry , Faculty of Medicine, Balikesir University , Balikesir , Turkey.
authors.forename: A A
authors.initials: AA
authors.lastname: Hismiogullari
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects*; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology*; D010179:Pancreas / Q000378:metabolism / Q000473:pathology*; D017208:Rats, Wistar
chemical_list: D001786:Blood Glucose; D007328:Insulin
keywords: high fat diet; insulin resistance; pancreas; skeletal muscle