Cittadini A, Grossman J D, Napoli R, Katz S E, Strömer H, Smith R J, Clark R, Morgan J P, Douglas P S
Department of Medicine (Cardiovascular Division), Beth Israel Hospital, Boston, Massachusetts 02215, USA.
J Am Coll Cardiol. 1997 Apr;29(5):1109-16. doi: 10.1016/s0735-1097(97)00010-7.
We sought to investigate the cardiac effects of growth hormone (GH) administration during the early phase of pathologic remodeling in a rat model of large myocardial infarction (MI).
Recent evidence suggests that exogenous administration of GH evokes a hypertrophic response and increases left ventricular (LV) function in vivo in rats with normal or chronically failing hearts. We hypothesized that these effects would attenuate ventricular remodeling early after MI.
Fifty-eight male rats underwent sham operation (n = 19) or had induced MI (n = 39). The day after the operation, the infarcted rats were randomized to receive 3 weeks of treatment with GH, 3 mg/kg body weight per day (n = 19) or placebo (n = 20). Echocardiography, catheterization and isolated whole heart preparations were used to define cardiac structure and function.
Growth hormone caused hypertrophy of the noninfarcted myocardium in a concentric pattern, as noted by higher echocardiographic relative wall thickness at 3 weeks and by morphometric histologic examination. Left ventricular dilation was reduced in the GH-treated versus placebo group (echocardiographic LV diastolic diameter to body weight ratio 2.9 +/- 0.1 vs. 3.5 +/- 0.2 cm/kg; p < 0.05). In vivo and in vitro cardiac function was improved after GH treatment. Despite elevated insulin-like growth factor-1 (IGF-1) serum levels in GH-treated rats, myocardial IGF-I messenger ribonucleic acid was not different among the three groups, suggesting that an increase in its local expression does not appear necessary to yield the observed effects.
These data demonstrate that early treatment of large MI with GH attenuates the early pathologic LV remodeling and improves LV function.
我们试图在大鼠大面积心肌梗死（MI）模型的病理重塑早期阶段，研究生长激素（GH）给药对心脏的影响。
最近的证据表明，外源性给予GH可在正常或慢性心力衰竭的大鼠体内引起肥厚反应并增加左心室（LV）功能。我们假设这些作用会在MI后早期减弱心室重塑。
58只雄性大鼠接受假手术（n = 19）或诱导MI（n = 39）。术后第二天，将梗死大鼠随机分为接受3周GH治疗组，每天3 mg/kg体重（n = 19）或安慰剂组（n = 20）。使用超声心动图、导管插入术和离体全心标本确定心脏结构和功能。
生长激素导致非梗死心肌呈同心性肥厚，3周时超声心动图相对室壁厚度增加以及形态学组织学检查均证实了这一点。与安慰剂组相比，GH治疗组的左心室扩张减少（超声心动图左心室舒张直径与体重比2.9 +/- 0.1 vs. 3.5 +/- 0.2 cm/kg；p < 0.05）。GH治疗后体内和体外心脏功能均得到改善。尽管GH治疗大鼠的胰岛素样生长因子-1（IGF-1）血清水平升高，但三组之间心肌IGF-I信使核糖核酸并无差异，这表明增加其局部表达似乎并非产生观察到的效应所必需。
这些数据表明，早期用GH治疗大面积MI可减弱早期病理性左心室重塑并改善左心室功能。
