Growth hormone stimulation of serum insulin concentration in cattle: Nutritional dependency and potential mechanisms
Growth hormone stimulation of serum insulin concentration in cattle: Nutritional dependency and potential mechanisms
复制标题
生长激素对牛血清胰岛素浓度的刺激：营养依赖性和潜在机制
DOI：
10.1016/j.domaniend.2009.03.003
复制
发表时间：
2009-08-01
影响因子：
2.1
通讯作者：
Jiang, H.
中科院分区：
文献类型：
--
作者：
Feng, J.;Gu, Z.;Jiang, H.
以前关于生长激素(GH)对牛血清胰岛素浓度影响的研究结果似乎相互矛盾，如果GH对牛血清胰岛素浓度产生影响，人们对GH影响牛血清胰岛素浓度的机制知之甚少。在本研究中，我们确定了GH对牛血清胰岛素浓度的影响是否受动物营养水平的影响，以及GH是否通过直接刺激胰岛素释放或胰岛胰岛素基因表达来增加牛血清胰岛素浓度。注射重组牛生长激素可提高非哺乳期、非妊娠肉牛的血清胰岛素浓度，但对只饲喂干草的奶牛没有影响。GH处理1 h和24 h均可提高生长牛胰岛培养物中的胰岛素浓度。生长激素处理24 h可增加培养的牛胰岛胰岛素基因的表达。生长激素处理16h后，报告基因在大鼠胰岛素分泌β细胞系中的表达增加，该报告基因由一个类似于1,500个碱基的牛胰岛素基因启动子引导。综上所述，这些结果表明外源GH可以提高牛的血清胰岛素浓度，但这种作用取决于饲喂牛的营养水平，GH通过刺激胰岛素的释放和胰岛胰岛素基因的表达来提高牛的血清胰岛素浓度。(C)2009 Elsevier Inc.保留所有权利。
Previous studies on the effect of growth hormone (GH) on serum insulin concentration in cattle had generated seemingly conflicting results, and little was known about the mechanism by which GH affects serum insulin concentration in cattle, if it does. In this study, we determined whether the effect of GH on serum insulin concentration in cattle could be affected by the nutritional levels of the animal and whether GH increased serum insulin concentration in cattle by directly stimulating insulin release or insulin gene expression in the pancreatic islets. Administration of recombinant bovine GH increased serum insulin concentration in nonlactating, nonpregnant beef cows fed a daily concentrate meal in addition to ad libitum hay, but it had no effect in those cows fed hay only. Both GH treatments for 1 and 24 h increased insulin concentrations in cultures of pancreatic islets isolated from growing cattle. Growth hormone treatment for 24 h increased insulin mRNA expression in cultured bovine pancreatic islets. Growth hormone treatment for 16 h increased reporter gene expression directed by a similar to 1,500-bp bovine insulin gene promoter in a rat insulin-producing beta cell line. Taken together, these results suggest that exogenous GH can increase serum insulin concentration in cattle, but this effect depends on the nutritional levels of fed cattle, and that GH increases serum insulin concentration in cattle by stimulating both insulin release and insulin gene expression in the pancreatic islets. (C) 2009 Elsevier Inc. All rights reserved.