Efeitos da restrição alimentar em ratos diabéticos : parâmetros fisiológicos, bioquímicos e morfológicos do intestino grosso

Abstract

Diabetes mellitus is a chronic disease due to the body's difficulty in metabolizing glucose, which may be a result of insulin resistance or deficiency in insulin production by pancreatic beta cells. Damages caused by diabetes are systemic and can be observed by changes in physiological, biochemical, and many other parameters, including the large intestine and its morphology.Considering that the incidence of diabetes is strongly related to lifestyle and eating habits, dietary restriction can be used as a strategy to manage and reduce the damage caused by diabetes mellitus.Thus, this study aimed to evaluate the effects of dietary restriction on the physiological, biochemical and morphophysiological parameters (intestinal wall and innervation) of the large intestine of diabetic rats. 20 male Wistar rats were divided into two groups (n = 10 / group): C (control) and D (diabetic) , And for diabetization the D group rats received intravenous injection of streptozotocin (35mg / kg).In the 0-2 month period (pre-restriction) group C received standard feed Nuvilab® and water ad libitum and group D received cafeteria-style diet (33% Nuvilab standard feed, 33% Nestlé ® condensed milk and 7% sugar) And water ad libitum.For the 3-4 month period (during food restriction), the C and D groups branched into C (control), CR (control with restriction), D (diabetic) and DR (diabetic with restriction) (n = 5 / group).All fed only standard feed, but the restriction groups received only 15g / day and the unrestricted groups received ad libitum feed. The physiological and biochemical parameters evaluated were: fasting glycemia, glucose tolerance test, insulin tolerance test, body mass, feed and water consumption, total proteins, frutosamine, triglycerides, total cholesterol, aspartate aminotransferase, Alanine aminotransferase and alkaline phosphatase, intestinal transit velocity.At the end of the treatment, intestinal parameters were also evaluated: tunica morphometry and total wall of the large intestine (proximal and distal colon), goblet cells index and quantification and morphometry of myenteric neurons (HuC/D+ and nNOS+). Groups D and DR showed the classic signs of diabetes, but the DR group showed significant improvements in the physiological and biochemical parameters evaluated: reduction in feed and water intake, improvement in lipid profile and liver enzymes, reduction of fasting glycemia and glycemic curves (ITT and GTT) with values also reduced when compared to group D. For morphometry of the intestinal tunics we observed more significant changes in group D in relation to the other groups. For morphometry and quantification of the general and nitrergic neuronal population the food restriction did not present significance, thus the damage caused by the diabetes on the intestinal wall and reduction in the neuronal population prevailed, and these parameters were not reversed in those groups submitted to food restriction.