Palmer R M, Flint D J, MacRae J C, Fairhurst F E, Bruce L A, Mackie S C, Lobley G E
Rowett Research Institute, Bucksburn, Aberdeen, U.K.
J Endocrinol. 1993 Dec;139(3):395-401. doi: 10.1677/joe.0.1390395.
Rats were injected twice daily for up to 10 days with GH or with a polyclonal antiserum to rat GH, commencing at 21-22 days of age. Administration of bovine or human GH (1mg/day) improved whole body growth rates by 22% and 29% respectively. Plantaris muscle mass was also increased, by 7 and 14% respectively. Anti-GH injected twice daily resulted in a 7% decrease in body weight at 4 days and a 10% reduction by 10 days. Similar decreases were observed in the total protein content of plantaris and soleus muscles. The decrease in the fractional rate of protein synthesis was proportionately greater than the decline in protein content in plantaris muscle whereas in the soleus no change in the rate of protein synthesis was observed, suggesting that the effect on this muscle was due to an increase in the rate of protein degradation. Serum total IGF-I was unchanged by treatment with either GH or anti-GH while the amount of hepatic IGF-I mRNA was also unaffected by anti-GH injection. These data are consistent with a direct effect of GH or an effect mediated by an autocrine/paracrine mechanism of action on muscle but do not support a role for serum total IGF-I as an endocrine mediator of GH action.
从21 - 22日龄开始，给大鼠每日注射两次生长激素（GH）或大鼠生长激素多克隆抗血清，持续10天。注射牛生长激素或人生长激素（1毫克/天）分别使全身生长速率提高了22%和29%。跖肌质量也分别增加了7%和14%。每日注射两次抗生长激素，4天时体重下降7%，10天时下降10%。跖肌和比目鱼肌的总蛋白含量也出现类似下降。跖肌中蛋白质合成分数速率的下降比例大于蛋白质含量的下降，而比目鱼肌中未观察到蛋白质合成速率的变化，这表明对该肌肉的影响是由于蛋白质降解速率增加所致。用生长激素或抗生长激素治疗后，血清总胰岛素样生长因子-I（IGF-I）未发生变化，抗生长激素注射也未影响肝脏IGF-I mRNA的量。这些数据与生长激素的直接作用或通过自分泌/旁分泌作用机制介导的对肌肉的作用一致，但不支持血清总IGF-I作为生长激素作用的内分泌介质发挥作用。
