Reduced serum concentrations of insulin-like growth factor-I (IGF-I) in protein-restricted growing rats are accompanied by reduced IGF-I mRNA levels in liver and skeletal muscle.
Reduced serum concentrations of insulin-like growth factor-I (IGF-I) in protein-restricted growing rats are accompanied by reduced IGF-I mRNA levels in liver and skeletal muscle.
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DOI：
10.1677/joe.0.1300305
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发表时间：
1991-08
期刊：
影响因子：
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通讯作者：
M. VandeHaar;B. Moats-Staats;M. Davenport;J. Walker;J. Ketelslegers;B. Sharma;L. Underwood
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文献类型：
--
作者：
M. VandeHaar;B. Moats-Staats;M. Davenport;J. Walker;J. Ketelslegers;B. Sharma;L. Underwood
在喂食低蛋白饮食的生长大鼠中，血清胰岛素样生长因子-I(IGF-I)浓度降低，这种下降与年龄有关，在较年轻的动物中更为明显。为了确定血清IGF-I的下降是否与IGF-I mRNA的下降有关，生长中的雌性大鼠被给予15%蛋白质充足或5%蛋白质缺乏的饮食，为期一周。蛋白质限制使4周龄大鼠体重增加减少44%(P<0.001)，血清胰岛素样生长因子-I浓度降低67%(P<0.001)，肝脏胰岛素样生长因子-I基因丰度降低51%(P<0.001)。在6周期间，蛋白质限制1周的摄食量增加了20%，体重增加没有变化，血清胰岛素样生长因子-I降低了38%(与6周对照组相比，P<0.001)，肝脏胰岛素样生长因子-I基因的表达降低了39%(P<0.001)。血清胰岛素样生长因子-I浓度与肝脏胰岛素样生长因子-I m RNA浓度呈高度正相关(r=0.8；P<0.001)。骨骼肌胰岛素样生长因子-I m RNA的丰度在蛋白质限制后也显著降低(4周时为37%，P<0.001；6周时为24%，P<0.001)，且与体重增长密切相关。肝脏生长激素结合蛋白和生长激素受体mRNA丰度在蛋白剥夺1周后在第6周下降，但在第4周没有下降。
The serum concentration of insulin-like growth factor-I (IGF-I) is reduced in growing rats fed a low-protein diet, and this decrease is age-dependent, being more pronounced in younger animals. To determine whether this decrease in serum IGF-I is related to a decrease in IGF-I mRNA, growing female rats were given free access to either a 15% protein-sufficient or a 5% protein-deficient diet for 1 week. Protein restriction in 4-week-old rats decreased body weight gain by 44% (P less than 0.001 compared with 4-week controls), serum IGF-I concentration by 67% (P less than 0.001) and liver IGF-I mRNA abundance by 51% (P less than 0.001). During week 6, protein restriction for 1 week resulted in a 20% increase in food intake with no change in weight gain, a 38% reduction in serum IGF-I (P less than 0.001 compared with 6-week controls) and a 39% decrease in liver IGF-I mRNA (P less than 0.001). The serum IGF-I concentration was highly correlated (r = 0.80; P less than 0.001) with the hepatic IGF-I mRNA concentration. Skeletal muscle IGF-I mRNA abundance was also decreased significantly by protein restriction (37% at week 4, P less than 0.001, and 24% at week 6, P less than 0.01) and was closely correlated (r = 0.71; P less than 0.001) with body weight gain. Liver GH-binding protein and GH receptor mRNA abundance were reduced by 1 week of protein deprivation at week 6 but not at week 4.(ABSTRACT TRUNCATED AT 250 WORDS)