Histochemical and ultrastructural analysis of hepatic glycogen and collagen fibers in alloxan-induced diabetic rats submitted to long-term physical training.

Alterations in liver functions are common among diabetic patients, and many symptoms in the liver have been reported, including changes in glycogen stores and in the amount of collagen fibers. The practice of physical training and its morphological effects in this organ, however, are scarcely studied. In order to observe the morphological effects of alloxan-induced diabetes and the alterations arising from the practice of long-term chronic physical training in the liver, samples were collected and processed, and then analyzed by means of the histochemical techniques Periodic Acid-Schiff and Picrosirius-Hematoxylin, and ultrastructural cytochemical test of Afzelius. Through evaluation of the tissue, it was observed a drastic reduction in hepatic glycogen stores of sedentary diabetics, recovered in trained diabetic rats. Furthermore, it was detected a decrease in the content of perisinusoidal collagen fibers in the diabetic liver, also recovered due to the development of a training protocol. On ultrastructural level, cytochemical analysis confirmed the loss of glycogen and the recovery obtained by training. In conclusion, the practice of a long-term chronic physical training protocol may be considered an important assistant in the treatment of diabetes, mitigating the occurrence of possible damages to liver tissue.

Collagen and reticular fibers in left ventricular muscle in diabetic rats: physical exercise prevents its changes?

Diabetic cardiomyopathy contributes to the high incidence of mortality in both types of diabetes. We aimed to investigate the histochemical aspects of collagen and reticular fibers in the cardiac muscle and evaluate the influence of physical exercise on these aspects. Wistar rats were divided in 4 groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Diabetes was induced with alloxan (35 mg/kg). Training program consisted of swimming 1h/day with a load of 4.8% of body weight for TD and 5.2% for TC, during 8 weeks. At the end of the experiment, samples of the left ventricle were collected, fixed in Bouin and processed on historesin. Sections were stained with periodic acid of Schiff, picrosirius-hematoxylin and ammoniacal silver. The PAS technique shows that individuals of group SD presented more intense reaction that the other groups. Picrosirius-hematoxylin technique showed a possible deposition of collagen fibers in SD. The TD group presented a reaction a lot similar to the controls' for both techniques', showing a possible prevention of this deposition. These results indicate that physical exercises might have an important role on the prevention of some negative alterations caused by experimental diabetes.