Palmer Amanda J, Chung Min-Yu, List Edward O, Walker Jennifer, Okada Shigeru, Kopchick John J, Berryman Darlene E
School of Human and Consumer Sciences, College of Health and Human Services, Edison Biotechnology Institute,Ohio University, Athens, Ohio 45701, USA.
Endocrinology. 2009 Mar;150(3):1353-60. doi: 10.1210/en.2008-1199. Epub 2008 Oct 23.
GH has a significant impact on body composition due to distinct anabolic and catabolic effects on lean and fat mass, respectively. Several studies have assessed body composition in mice expressing a GH transgene. Whereas all studies report enhanced growth of transgenic mice as compared with littermate controls, there are inconsistencies in terms of the relative proportion of lean mass to fat mass in these animals. The purpose of this study was to characterize the accumulation of adipose and lean mass with age and according to gender in a bovine (b) GH transgenic mouse line. Weight and body composition measurements were assessed in male and female bGH mice with corresponding littermate controls in the C57BL/6J genetic background. Body composition measurements began at 6 wk and continued through 1 yr of age. At the conclusion of the study, tissue weights were determined and triglyceride content was quantified in liver and kidney. Although body weights for bGH mice were significantly greater than their corresponding littermate controls at all time points, body composition measurements revealed an unexpected transition midway through analyses. That is, younger bGH mice had relatively more fat mass than nontransgenic littermates, whereas bGH mice became significantly leaner than controls by 4 months in males and 6 months in females. These results reveal the importance in timing and gender when conducting studies related to body composition or lean and fat tissue in GH transgenic mice or in other genetically manipulated mouse strains in which body composition may be impacted.
生长激素（GH）对身体成分有显著影响，因为它分别对瘦体重和脂肪量有明显的合成代谢和分解代谢作用。多项研究评估了表达GH转基因的小鼠的身体成分。尽管所有研究都报告称，与同窝对照相比，转基因小鼠的生长有所增强，但这些动物的瘦体重与脂肪量的相对比例存在不一致之处。本研究的目的是在一个牛（b）GH转基因小鼠品系中，根据年龄和性别来描述脂肪和瘦体重的积累情况。在C57BL/6J遗传背景下，对雄性和雌性bGH小鼠及其相应的同窝对照进行体重和身体成分测量。身体成分测量从6周龄开始，持续到1岁。在研究结束时，测定组织重量，并对肝脏和肾脏中的甘油三酯含量进行定量。尽管在所有时间点，bGH小鼠的体重均显著高于其相应的同窝对照，但身体成分测量结果显示，在分析过程中出现了意想不到的转变。也就是说，较年轻的bGH小鼠比非转基因同窝小鼠的脂肪量相对更多，而在雄性中，4个月大时，在雌性中，6个月大时，bGH小鼠变得比对照明显更瘦。这些结果揭示了在对GH转基因小鼠或其他可能影响身体成分的基因操作小鼠品系进行与身体成分或瘦组织和脂肪组织相关的研究时，时间和性别的重要性。
