Rocha F L, Carmo E C, Roque F R, Hashimoto N Y, Rossoni L V, Frimm C, Anéas I, Negrão C E, Krieger J E, Oliveira E M
Laboratory of Biochemistry, School of Physical Education and Sport, Avenida Prof. Mello Moraes 65, Butantã, Cidade Universitária, CEP 05508-9000 São Paulo, Brazil.
Am J Physiol Heart Circ Physiol. 2007 Dec;293(6):H3575-83. doi: 10.1152/ajpheart.01251.2006. Epub 2007 Sep 28.
We evaluated the effects of swimming and anabolic steroids (AS) on ventricular function, collagen synthesis, and the local renin-angiotensin system in rats. Male Wistar rats were randomized into control (C), steroid (S; nandrolone decanoate; 5 mg/kg sc, 2x/wk), steroid + losartan (SL; 20 mg.kg(-1).day(-1)), trained (T), trained + steroid (T+S), and trained + steroid + losartan (T+SL; n = 14/group) groups. Swimming was performed 5 times/wk for 10 wk. Serum testosterone increased in S and T+S. Resting heart rate was lower in T and T+S. Percent change in left ventricular (LV) weight-to-body weight ratio increased in S, T, and T+S. LV systolic pressure declined in S and T+S. LV contractility increased in T (P < 0.05). LV relaxation increased in T (P < 0.05). It was significantly lower in T+S compared with C. Collagen volumetric fraction (CVF) and hydroxyproline were higher in S and T+S than in C and T (P < 0.05), and the CVF and LV hypertrophy were prevented by losartan treatment. LV-ANG I-converting enzyme activity increased (28%) in the S group (33%), and type III collagen synthesis increased (56%) in T+S but not in T group. A positive correlation existed between LV-ANG I-converting enzyme activity and collagen type III expression (r(2) = 0.88; P < 0.05, for all groups). The ANG II and angiotensin type 1a receptor expression increased in the S and T+S groups but not in T group. Supraphysiological doses of AS exacerbated the cardiac hypertrophy in exercise-trained rats. Exercise training associated with AS induces maladaptive remodeling and further deterioration in cardiac performance. Exercise training associated with AS causes loss of the beneficial effects in LV function induced by exercising. These results suggest that aerobic exercise plus AS increases cardiac collagen content associated with activation of the local renin-angiotensin system.
我们评估了游泳和合成代谢类固醇（AS）对大鼠心室功能、胶原蛋白合成及局部肾素 - 血管紧张素系统的影响。雄性Wistar大鼠被随机分为对照组（C）、类固醇组（S；癸酸诺龙；5 mg/kg皮下注射，每周2次）、类固醇 + 氯沙坦组（SL；20 mg·kg⁻¹·d⁻¹）、训练组（T）、训练 + 类固醇组（T + S）和训练 + 类固醇 + 氯沙坦组（T + SL；每组n = 14）。每周游泳5次，共10周。S组和T + S组血清睾酮升高。T组和T + S组静息心率降低。S组、T组和T + S组左心室（LV）重量与体重之比的变化百分比增加。S组和T + S组左心室收缩压下降。T组左心室收缩力增加（P < 0.05）。T组左心室舒张增加（P < 0.05）。与C组相比，T + S组显著降低。S组和T + S组的胶原蛋白体积分数（CVF）和羟脯氨酸高于C组和T组（P < 0.05），氯沙坦治疗可预防CVF和左心室肥厚。S组左心室血管紧张素I转换酶活性增加（28%），T + S组III型胶原蛋白合成增加（56%），而T组未增加。左心室血管紧张素I转换酶活性与III型胶原蛋白表达之间存在正相关（r² = 0.88；所有组P < 0.05）。S组和T + S组血管紧张素II和血管紧张素1a受体表达增加，而T组未增加。超生理剂量的AS加剧了运动训练大鼠的心脏肥厚。与AS相关的运动训练诱导适应性不良重塑并导致心脏功能进一步恶化。与AS相关的运动训练导致运动诱导的左心室功能有益效应丧失。这些结果表明有氧运动加AS会增加与局部肾素 - 血管紧张素系统激活相关的心脏胶原蛋白含量。
