Interferência do treinamento em natação com diferentes intensidades na carcinogênese experimental do cólon

• Autor(a) principal: Lunz, Wellington
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2776
• topic: Carcinogênese; Cólon; Exercício; Carcinogenesis; Colon; Exercise; CNPQ::CIENCIAS DA SAUDE

The aims of this study were: a) to quantify, to classify and to correlate aberrant crypts foci (ACF) and tumors, in rats with 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis; b) to test whether swimming training at different intensities would affect the number of ACF, number, incidence and size of the tumors, food intake, body weight gain, body composition (fat, protein and water), the levels of serum glucose, total cholesterol (CT), triacylglycerides (TAG), high, low and very low density lipoproteins (HDL, LDL and VLDL) and C-reactive protein (PCR) in animals with DMH- induced carcinogenesis; c) to verify if the fat percentual (carcass and intra-abdominal), glucose and lipidic profile (CT, TAG, HDL, LDL and VLDL) would associate with the number of tumors and ACF; d) to verify if tumor incidence would affect the levels of PCR. Wistar male rats (n=52), 11 week old, were divided into two sedentary groups, with (CE n=10) and without (CD n=6) drug, and three exercised groups, without overload (ED1 n=12), with overload of 2% (ED2 n=12) and 4% (ED3 n=12) of the animal body weight. Animals from ED1, ED2 and ED3 underwent a progressive swimming training program, 5-20 min/day, 5 days/week, for 35 weeks. All exercised animals and those from CE group, received 4 DMH injections (40 mg.kg-1) at the first two weeks of experiment. All animals had free access to water and commercial chow. The results showed that food intake was not statistically different between groups. The body weight gain in animals from CD group was significantly higher than in those from CE, ED1, ED2 and ED3 groups. The percentage of intra-abdominal fat was statistically higher in CD group animals as compared to ED1 and ED3 group. The carcass fat percentage in CD group was significantly higher than in CE, ED1, ED2 and ED3 groups. The water percentage in the carcass was significantly lower in animals from CD group as compared to those in CE, ED1, ED2 and ED3 groups. The carcass protein percentage was not statistically different between groups. Total cholesterol and LDL serum concentrations were higher in CD group than in CE, ED1, ED2 and ED3 groups. Triacylglycerides and VLDL serum concentrations were higher in CD group as compared to ED3 group. The serum concentration of HDL was higher in CD group as compared to CE, ED1 and ED3 groups. The serum concentration of glucose was not statistically different between groups. There was no statistic difference among CE, ED1, ED2 and ED3 groups for PCR. Animals with tumor incidence ( 1) did not present statistical difference in PCR frequency as compared to those with no incidence. Negative associations of the tumor number with carcass and intra- abdominal fat percentual and glucose were observed. There were, in a general way, positive associations of the tumor number with CT, HDL, LDL, VLDL and TAG, but not sufficiently strong (r or rs < 0.60). Positive associations of ACF with CT, HDL, LDL, VLDL and TAG were found, but were usually weak (r or rs <0.30) or regular (r or rs 0.30 0.60) associations. A higher number of ACF and tumors was found in the medial and distal regions of the large intestine in all injected animals. Moderate intensity exercise (ED2) presented a lower number of ACF in the proximal and distal regions, lower mean of ACF and lower number of ACF 3 as compared to those from CE group. There was no statistical difference between groups for the number of ACF 3. Potency, relative risk, reduction percentual of ACF, and potency of ACF size reduction, were greater in animals from ED2, followed by ED1 and ED3 groups. The number, incidence and size of the tumors were not affected by exercise at any studied intensities. ACF number was positively associated with the number of tumors. These results suggest that: 1) ACF and tumors are located more frequently in the medial and distal regions of the large intestine; 2) exercise, at the studied intensities, do not affect the number, incidence and size of tumors, as well as food intake, body weight gain, body composition, lipidic profile, glucose and PCR in animals with DMH-induced colorectal carcinogenesis; 3) moderate intensity exercise provide protection against DMHinduced ACF; 4) The serum concentration of glucose and the fat percentage are not positively associated with the number of tumors in the large intestine; 5) the number of tumors are not associated with CT, TAG, LDL, VLDL and HDL; 6) the PCR response is not affected by the incidence of colorectal tumors.