Revista Brasileira de Medicina do Esporte
On-line version ISSN 1806-9940
EGUCHI, Ricardo et al. Effects of the chronic exercise on the circulating concentration of leptin and ghrelin in rats With diet-induced obesity. Rev Bras Med Esporte [online]. 2008, vol.14, n.3, pp. 182-187. ISSN 1806-9940. http://dx.doi.org/10.1590/S1517-86922008000300004.
Obesity is becoming one of the biggest worldwide epidemics. Therefore, knowing its etiology and mechanisms that regulate its development is of great relevance for its treatment. Thus, the aim of the present study was to evaluate the effects of obesity induced by the palatable hyperlipidic diet and of the chronic physical activity in rats, on the adiposity and the serum concentration of regulating hormones of the energy balance (leptin and ghrelin). 32 male Wistar rats were divided in four groups: Sedentary fed with chow diet (SN), sedentary fed with cafeteria diet (SC), trained fed with chow diet (TN) and trained fed with cafeteria diet (TC). The cafeteria diet led to a significant increase of central (RET) and visceral (EPI) adiposity (p<0.05). Conversely,the exercise training minimized the effect of the cafeteria diet, diminishing the central and visceral adiposity. Leptin was also increased in the groups fed with the cafeteria diet, suggesting increase of the resistance to the action of this hormone. Chronic physical activity did not hinder the development of hyperleptinemia. Reduction in the serum ghrelin concentration was observed only in the normocaloric group. Therefore,it has been concluded that the quality of diet and the quantity of adipose tissue mass behaved as important regulators of the serum concentration of leptin and ghrelin, reinforcing the importance of a suitable diet and continuous physical activity in the maintenance of body weight in the combat to the deleterious effects of obesity.
Keywords : obesity; palatable hyperlipidic diet; exercise; energy balance; ghrelin; leptin.