Universidade Nove de Julho-UNINOVE, São Paulo, SP, Brasil.
Braz J Med Biol Res. 2013 May;46(5):447-53. doi: 10.1590/1414-431X20122111. Epub 2013 May 24.
This study tested the hypothesis that simvastatin treatment can improve cardiovascular and autonomic functions and membrane lipoperoxidation, with an increased effect when applied to physically trained ovariectomized rats. Ovariectomized rats were divided into sedentary, sedentary+simvastatin and trained+simvastatin groups (n = 8 each). Exercise training was performed on a treadmill for 8 weeks and simvastatin (5 mg/kg) was administered in the last 2 weeks. Blood pressure (BP) was recorded in conscious animals. Baroreflex sensitivity was evaluated by the tachycardic and bradycardic responses to BP changes. Cardiac vagal and sympathetic effects were determined using methylatropine and propranolol. Oxidative stress was evaluated based on heart and liver lipoperoxidation using the chemiluminescence method. The simvastatin-treated groups presented reduced body weight and mean BP (trained+simvastatin = 99 ± 2 and sedentary+simvastatin = 107 ± 2 mmHg) compared to the sedentary group (122 ± 1 mmHg). Furthermore, the trained group showed lower BP and heart rate compared to the other groups. Tachycardic and bradycardic responses were enhanced in both simvastatin-treated groups. The vagal effect was increased in the trained+simvastatin group and the sympathetic effect was decreased in the sedentary+simvastatin group. Hepatic lipoperoxidation was reduced in sedentary+simvastatin (≈21%) and trained+simvastatin groups (≈57%) compared to the sedentary group. Correlation analysis involving all animals demonstrated that cardiac lipoperoxidation was negatively related to the vagal effect (r = -0.7) and positively correlated to the sympathetic effect (r = 0.7). In conclusion, improvement in cardiovascular and autonomic functions associated with a reduction of lipoperoxidation with simvastatin treatment was increased in trained ovariectomized rats.
本研究旨在验证辛伐他汀治疗可改善心血管和自主神经功能以及膜脂质过氧化,且在对经过锻炼的去卵巢大鼠进行治疗时效果更为显著这一假说。将去卵巢大鼠分为安静组、安静+辛伐他汀组和训练+辛伐他汀组(每组 8 只)。对训练组大鼠进行 8 周的跑步机训练,并在最后 2 周给予辛伐他汀(5mg/kg)。在清醒动物中记录血压(BP)。通过 BP 变化引起的心动过速和心动过缓反应评估压力感受性反射敏感性。使用甲基阿托品和普萘洛尔确定心脏迷走神经和交感神经的影响。通过化学发光法评估心脏和肝脏脂质过氧化的氧化应激。与安静组(122 ± 1mmHg)相比,辛伐他汀治疗组大鼠体重和平均 BP 降低(训练+辛伐他汀组=99 ± 2mmHg,安静+辛伐他汀组=107 ± 2mmHg)。此外,与其他组相比,训练组大鼠的 BP 和心率更低。在两个辛伐他汀治疗组中,心动过速和心动过缓反应均增强。在训练+辛伐他汀组中,迷走神经效应增加,而在安静+辛伐他汀组中,交感神经效应降低。与安静组相比,安静+辛伐他汀组(约 21%)和训练+辛伐他汀组(约 57%)的肝脂质过氧化减少。对所有动物进行的相关性分析表明,心脏脂质过氧化与迷走神经效应呈负相关(r=-0.7),与交感神经效应呈正相关(r=0.7)。综上所述,辛伐他汀治疗可改善心血管和自主神经功能,同时降低脂质过氧化,而这种改善作用在经过锻炼的去卵巢大鼠中更为显著。