Lunz W, Peluzio M C G, Dias C M G C, Moreira A P B, Natali A J
Departamento de Nutrição e Saúde, Universidade Federal de Viçosa, 36570-000 Viçosa, MG, Brasil.
Braz J Med Biol Res. 2008 Nov;41(11):1000-4. doi: 10.1590/s0100-879x2008001100009.
We determined the effect of long-term aerobic swimming training regimens of different intensities on colonic carcinogenesis in rats. Male Wistar rats (11 weeks old) were given 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethyl-hydrazine (DMH, dissolved in 0.9% NaCl containing 1.5% EDTA, pH 6.5), at 3-day intervals and divided into three exercise groups that swam with 0% body weight (EG1, N = 11), 2% body weight (EG2, N = 11), and 4% body weight of load (EG3, N = 10), 20 min/day, 5 days/week for 35 weeks, and one sedentary control group (CG, N = 10). At sacrifice, the colon was removed and counted for tumors and aberrant crypt foci. Tumor size was measured and intra-abdominal fat was weighed. The mean number of aberrant crypt foci was reduced only for EG2 compared to CG (26.21 +/- 2.99 vs 36.40 +/- 1.53 crypts; P < 0.05). Tumor incidence was not significantly different among groups (CG: 90%; EG1: 72.7%; EG2: 90%; EG3: 80%). Swimming training did not affect either tumor multiplicity (CG: 2.30 +/- 0.58; EG1: 2.09 +/- 0.44; EG2: 1.27 +/- 0.19; EG3: 1.50 +/- 0.48 tumors) or size (CG: 1.78 +/- 0.24; EG1: 1.81 +/- 0.14; EG2: 1.55 +/- 0.21; EG3: 2.17 +/- 0.22 cm(3)). Intra-abdominal fat was not significantly different among groups (CG: 10.54 +/- 2.73; EG1: 6.12 +/- 1.15; EG2: 7.85 +/- 1.24; EG3: 5.11 +/- 0.74 g). Aerobic swimming training with 2% body weight of load protected against the DMH-induced preneoplastic colon lesions, but not against tumor development in the rat.
我们确定了不同强度的长期有氧游泳训练方案对大鼠结肠癌发生的影响。雄性Wistar大鼠（11周龄）每隔3天皮下注射4次1,2 - 二甲基肼（DMH，40毫克/千克体重，溶解于含1.5%乙二胺四乙酸、pH值为6.5的0.9%氯化钠溶液中），并分为三个运动组，分别背负0%体重（EG1，N = 11）、2%体重（EG2，N = 11）和4%体重的负荷（EG3，N = 10）游泳，每天20分钟，每周5天，持续35周，以及一个久坐对照组（CG，N = 10）。处死时，取出结肠并计数肿瘤和异常隐窝病灶。测量肿瘤大小并称量腹内脂肪重量。与CG组相比，只有EG2组的异常隐窝病灶平均数减少（26.21±2.99个隐窝对36.40±1.53个隐窝；P < 0.05）。各组之间的肿瘤发生率无显著差异（CG组：90%；EG1组：72.7%；EG2组：90%；EG3组：80%）。游泳训练对肿瘤数量（CG组：2.30±0.58个；EG1组：2.09±0.44个；EG2组：1.27±0.19个；EG3组：1.50±0.48个肿瘤）或大小（CG组：1.78±0.24立方厘米；EG1组：1.81±0.14立方厘米；EG2组：1.55±0.21立方厘米；EG3组：2.17±0.22立方厘米）均无影响。各组之间的腹内脂肪无显著差异（CG组：10.54±2.73克；EG1组：6.12±1.15克；EG2组：7.85±1.24克；EG3组：5.11±0.74克）。背负2%体重负荷的有氧游泳训练可预防DMH诱导的大鼠结肠癌前病变，但对肿瘤发展无预防作用。
