Estudo morfológico do músculo extensor longo dos dedos da prole de ratas obesas submetidas ou não à cirurgia de derivação gástrica em Y de Roux

Abstract

Studies show that maternal obesity can affect fetal development, resulting in diseases in adult life, such as diabetes mellitus type 2, cardiovascular disease, obesity itslef. To reduce the effects of obesity and its comorbidities, bariatric surgeries stand out among the most effective interventions, with Roux-en-Y gastric bypass (RYGB) being the most frequently performed type of bariatric procedure. However, there are still few studies in the literature that evaluate the effects of obesity and bariatric surgeries on the morphology of skeletal muscle tissue in adult offspring. Thus, the objective of this study was to evaluate microscopic parameters of muscle fibers and neuromuscular junctions (NMJs) of the extensor digitorum longus muscle (EDL) in obese rats’ offspring submitted or not to RYGB surgery. Three-week Wistar rats were randomly divided into three groups: Control Group (CTL) which received a standard diet; 2) Cafeteria False Operated (CAF FO) and 3) Cafeteria RYGB (CAF RYGB), the latter two received a cafeteria diet before and after the surgical procedure until the weaning of the offspring. In the 18th of life, the surgical procedure and false operation were performed in the CAF RYGB and CAF FO groups, respectively. The mating of the animals occurred five weeks after the surgical procedure. The birth of the offspring was postnatal day 0, and weaning occurred at three weeks of age, and only the male offspring were separated for the experiment. The offspring of the first generation (F1) were named CTL-F1, OB-F1, CAF FO-F1 and CAF RYGB and received standard diet. At 17 weeks the animals were euthanized and the EDL muscle collected for analysis of fiber muscles and NMJs. When the CTL-F1 and OB-F1 groups were analyzed, the latter had an increase in body weight, retroperitoneal and periepididymal fats, and capillary/fiber ratio. Reduction in the number of nuclei, conjunctive and morphological changes in the parameters evaluated in the ultrastructure. The area and larger diameter of NMJs also showed reduction. The analysis between CAF RYGB-F1 and CAF FO-F1 groups showed reduction of body weight, ELD muscle weight, retroperitoneal and periepididimal fat, nasoanal length, fiber area and nuclei/fiber ratio in the CAF RYGB-F1 group. This group also presented increase in the number of fibers of type I and IIa and number of capillaries, as well as reduction in the area of the NMJs and morphological alterations in the ultrastructure. These results demonstrate that both obesity and bariatric surgery expose the offspring, through metabolic programming, to effects on the morphology of skeletal muscle tissue, being found greater aggravations in the muscular fiber of the offspring of mothers submitted to RYGB.