Área de adipócitos e parâmetros bioquímicos de ratos submetidos à dieta hiperlipídica e exercício aeróbio

Abstract

Objective: To study the effects of hypercaloric/hyperlipidic diets (chocolate and baru) associated to aerobic exercise on different fat depots as well as on substrates tissue of Wistar rats. Methods: After weaning, the animals, except the controls (NUVILAB® diet: 3.48kcal/g), were fed with a chocolate diet (4.17 kcal/g) during 2 months in order to induce obesity. After this period the animals were distributed into 6 groups: Sedentary Control (SC); Trained Control (TC); Sedentary Baru (SB); Trained Baru (TB); Sedentary Chocolate (SCho) and Trained Chocolate (TCho), according to the introduction of baru extract diet as well as of swimming training (supporting overload equivalent to 2% of body weight, during 8 wk, 5d/wk, and 1h/session). Body weight and food intake were recorded weekly. After the death of the animals, serum free fatty acids (FFA), hepatic and muscular triglycerides and glycogen (TGLmusc, TGLhep, GLICmusc, GLIChep) content were determined. The retroperitoneal (RET), inguinal (IN), and omental (OM) fat tissues were excised, weighted, and submitted to histological and adipocyte area evaluation. Results: The weight gain induced by hypercaloric/hyperlipidic diets was attenuated by exercise (SB 71.14±20,71 > TB 37.14±21,11; SCHO 54.94±18,70 > TCHO 22.30±17,14). The hypercaloric/hyperlipidic diet increased weight and cell areas of RET if compared to control diet (P<0.05). The physical training decreased the OM (TCho: 6,370.91 ± 7,776.13 < SCho: 7,341.28 ± 2.24 μm2) and IN (TCho: 5,147.49 ± 5,712.71 < SCho: 7,083.11±7,682.40 μm2) cell areas of chocolate group as well as IN cell areas of TC (TE: 2,212.87 ± 1,920.34 < SC: 3,386.11 ± 3,973.09μm2). The prevalence of hepatic steatosis was higher in sedentary rats fed with hypercaloric/hyperlipidic if compared to control group (CHOS:83%>BS:80%> CS:50%). The trained animals showed lower TGLhep content in relation to sedentary rats under continuous hypercaloric/hyperlipidic diets (SB: 1.36 ± 0.50 > TB: 0.88 ± 0.43mg.100mg-1; SCho: 1.77 ± 0.64 > TCho: 0.86 ± 0.41mg.100mg-1). The hypercaloric/hyperlipidic baru diet induced TGmusc deposition (p<0,05), in both, sedentary and trained rats, compared to controls. Conclusion: Light to moderate physical training prevented weight and TGLhep accumulation in rats fed with hypercaloric/hyperlipidic diet. Abdominal tissues were more sensitive to hyperlipidic diet compared to peripheric subcutaneous fat tissue. On the other hand, the effects of exercise were more pronounced in visceral and inguinal fat depots.