Histological and histochemical studies on the effect of alloxan induced diabetes on the skeletal muscles of the rabbit

The present work deals with the histological and histochemical changes in the rabbit gastrocnemius muscle fibers due to alloxan induced diabetes. Thirty healthy male New Zealand rabbits were utilized. The rabbits were divided into two groups; The Animals of the control group [ten rabbits] were injected singly with sterile saline [1 mI/kg body weight] in their ear veins. Each animal of the experimental diabetic group [twenty animals] was injected with a single dose of Alloxan [100 mg dissolved in 1 mI sterile saline/kg body weight] in 1 st ear vein to induce diabetes. The experimental group was further subdivided into two subgroups; [a] Subgroups B: were sacrificed 8 weeks after Alloxan injection. 1b] Subgroup B: they were sacrificed 16 weeks after Alloxan injection. Specimens from gastrocnemius muscles of all animals were prepared for histochemical staining. Other specimens were also prepared for transmission electron microscope examination. The collagen fibers between the muscle fibers were increased in diabetic animals. Electron microscopy revealed a marked decrease in the number of mitochondria, the cristae of which were also diminished or oven lost, moreover, the electron-dense granules in the mitochondrial matrix were increased. Thickening of the basement membrane of the muscle capillaries was also noticed in the diabetic animals. Regarding the histochemical changes of the muscle fibers of diabetic animals; it was found that the glycogen content of these fibers was deceased, while the lipid content was unchanged. The activities of both, Alkaline phosphatase and Acid phosphatase enzymes were increased, but the activity of Succinc dehydrogenase enzyme was markedly diminished. No changes could be detected in the activity of Adenosine triphosphatase enzyme in the diabetic muscle fibers. This work concluded that diabetes mellitus has serious effects of the muscle fibers affecting mainly the mitochondria and the oxidative enzymes resulting in weak contractility and rapid fatigue of the muscles