Post Graduation Course, Department of Clinical and Cardiology, School of Medicine, São Paulo State University, UNESP, Botucatu, São Paulo, Brazil.
Horm Metab Res. 2011 Jun;43(6):397-403. doi: 10.1055/s-0031-1273769. Epub 2011 Mar 29.
This study investigated the effects of growth hormone therapy on energy expenditure, lipid profile, oxidative stress and cardiac energy metabolism in aging and obesity conditions. Life expectancy is increasing in world population and with it, the incidence of public health problems such as obesity and cardiac alterations. Because growth hormone (GH) concentration is referred to be decreased in aging conditions, a question must be addressed: what is the effect of GH on aging related adverse changes? To investigate the effects of GH on cardiac energy metabolism and its association with calorimetric parameters, lipid profile and oxidative stress in aged and obese rats, initially 32 male Wistar rats were divided into 2 groups (n=16), C: given standard-chow and water; H: given hypercaloric-chow and receiving 30% sucrose in its drinking water. After 45 days, both C and H groups were divided into 2 subgroups (n=8), C+PL: standard-chow, water, and receiving saline subcutaneously; C+GH: standard-chow, water, and receiving 2 mg/kg/day rhGH subcutaneously; H+PL: hypercaloric-chow, 30% sucrose, receiving saline subcutaneously; H+GH: hypercaloric-chow, 30% sucrose, receiving rhGH subcutaneously. After 30 days, C+GH and H+PL rats had higher body mass index, Lee-index, body fat content, percent-adiposity, serum triacylglycerol, cardiac lipid-hydroperoxide, and triacylglycerol than C+PL. Energy-expenditure (RMR)/body weight, oxygen consumption and fat-oxidation were higher in H+GH than in H+PL. LDL-cholesterol was highest in H+GH rats, whereas cardiac pyruvate-dehydrogenase and phosphofrutokinase were higher in H+GH and H+PL rats than in C+PL. In conclusion, the present study brought new insights on aging and obesity, demonstrating for the first time that GH therapy was harmful in aged and obesity conditions, impairing calorimetric parameters and lipid profile. GH was disadvantageous in control old rats, having undesirable effects on triacylglycerol accumulation and cardiac oxidative stress.
本研究探讨了生长激素治疗对衰老和肥胖条件下能量消耗、脂质谱、氧化应激和心脏能量代谢的影响。世界人口的预期寿命正在增加，随之而来的是肥胖和心脏改变等公共卫生问题的发生率。由于生长激素 (GH) 浓度在衰老条件下降低，因此必须提出一个问题：GH 对与衰老相关的不利变化有什么影响？为了研究 GH 对心脏能量代谢的影响及其与热量参数、脂质谱和氧化应激的关系，我们最初将 32 只雄性 Wistar 大鼠分为 2 组（n=16），C 组给予标准饲料和水；H 组给予高热量饲料，并在饮用水中摄入 30%的蔗糖。45 天后，C 和 H 两组又分为 2 个亚组（n=8），C+PL 组给予标准饲料、水，皮下注射生理盐水；C+GH 组给予标准饲料、水，皮下注射 2mg/kg/d 的 rhGH；H+PL 组给予高热量饲料、30%的蔗糖，皮下注射生理盐水；H+GH 组给予高热量饲料、30%的蔗糖，皮下注射 rhGH。30 天后，C+GH 和 H+PL 组大鼠的体重指数、Lee 指数、体脂含量、体脂率、血清三酰甘油、心脏脂质过氧化物和三酰甘油均高于 C+PL 组。H+GH 组大鼠的能量消耗（静息代谢率）/体重、耗氧量和脂肪氧化率高于 H+PL 组。H+GH 组大鼠的 LDL 胆固醇最高，而 H+GH 和 H+PL 组大鼠的心脏丙酮酸脱氢酶和磷酸果糖激酶均高于 C+PL 组。综上所述，本研究为衰老和肥胖带来了新的见解，首次证明 GH 治疗在衰老和肥胖条件下是有害的，会损害热量参数和脂质谱。GH 对年老的对照组大鼠是不利的，对甘油三酯的积累和心脏氧化应激有不良影响。
