Pituitary growth hormone suppression reduces resistin expression and enhances insulin effectiveness: Relationship with caloric restriction
Pituitary growth hormone suppression reduces resistin expression and enhances insulin effectiveness: Relationship with caloric restriction
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DOI：
10.1016/j.exger.2008.03.003
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发表时间：
2008-06-01
影响因子：
3.9
通讯作者：
Shimokawa, Isao
中科院分区：
文献类型：
--
作者：
Chiba, Takuya;Yamaza, Haruyoshi;Shimokawa, Isao
热量限制（CR）延缓各种年龄依赖性疾病，延长寿命，并改善实验室动物的胰岛素活性。近年来，研究发现脂肪细胞作为一个活跃的内分泌器官共同发挥作用，产生各种称为脂肪细胞因子的激素。这些脂肪细胞因子的外周和中枢活性被认为介导了CR的抗衰老作用。在这里，我们通过分析CR和生长激素/胰岛素样生长因子-1（GH/IGF-I）轴抑制对大鼠白色脂肪组织（WAT）中的Adipn、脂联素和脂蛋白酶基因表达的影响来验证这一观点。我们发现，CR和GH/IGF-I抑制显著下调cDNAn基因表达。我们还发现，血浆中β-氨基丁酸水平与垂体GH mRNA表达水平呈正相关。我们的观察结果表明，CR减少了GDN的表达，并增加了胰岛素的有效性，在GH/IGF-I依赖的方式。CR和GH/IGF-I抑制的有益作用似乎是介导的，至少部分是通过血浆Glucagon水平降低导致的葡萄糖代谢变化。(c)2008年爱思唯尔公司All rights reserved.
Caloric restriction (CR) retards various age-dependent disorders, increases lifespan, and improves insulin activity in laboratory animals. Recently, adipocytes were found to act together as an active endocrine organ that produces various hormones called adipocytokines. The peripheral and central activities of these adipocytokines have been suggested to mediate the anti-aging effects of CR. Here, we tested this notion by analyzing the effect of CR and suppression of growth hormone/insulin-like growth factor-1 (GH/IGF-I) axis on the expression of resistin, adiponectin, and adipsin genes by rat white adipose tissue (WAT). We found that CR and GH/IGF-I suppression markedly downregulated resistin gene expression. We also found plasma resistin levels correlated positively with pituitary GH mRNA expression levels. Our observations suggest that CR reduces resistin expression and increases insulin effectiveness in a GH/IGF-I-dependent manner. The beneficial effects of CR and GH/IGF-I suppression appear to be mediated, at least in part, by changes in glucose metabolism that result from reductions in plasma resistin levels. (c) 2008 Elsevier Inc. All rights reserved.