Ahmad I, Steggles A W, Carrillo A J, Finkelstein J A
Department of Anatomy, Northeastern Ohio Universities, College of Medicine, Rootstown 44272.
J Cell Biochem. 1990 May;43(1):59-66. doi: 10.1002/jcb.240430106.
Levels of pituitary growth hormone (GH) messenger RNA (mRNA) were compared in groups of genetically obese (fa/fa) and lean (Fa/-) littermate male Zucker rats at four different ages, 3, 5, 9, and 11 weeks, in order to determine the earliest age at which a difference between the two groups could be detected. No difference was seen in three-week-old animals. Five weeks of age was the earliest time at which the level of GH mRNA was significantly decreased in the obese rats; this decrease was present at all subsequent ages. Mean serum growth hormone levels were lower in obese animals at all ages, but the differences were not statistically significant because of the large individual variation associated with the pulsatile nature of GH release. The earliest occurrence of differences in GH mRNA level is later than some of the obesity associated abnormalities present in adipose tissue. The earliest time of the GH mRNA differences can be associated with the time when decreased protein deposition is initially seen in the obese rats. Because of this association, decreased GH mRNA may enhance the development of obesity.
为了确定能够检测到两组之间差异的最早年龄，对3周、5周、9周和11周龄这四个不同年龄段的遗传性肥胖（fa/fa）和瘦型（Fa/-）同窝雄性 Zucker 大鼠的垂体生长激素（GH）信使核糖核酸（mRNA）水平进行了比较。在3周龄的动物中未观察到差异。5周龄是肥胖大鼠中GH mRNA水平显著降低的最早时间；在所有随后的年龄段均存在这种降低。肥胖动物在所有年龄段的平均血清生长激素水平均较低，但由于与GH释放的脉冲性质相关的个体差异较大，这些差异无统计学意义。GH mRNA水平差异的最早出现时间晚于脂肪组织中存在的一些与肥胖相关的异常情况。GH mRNA差异的最早时间可能与肥胖大鼠最初出现蛋白质沉积减少的时间相关。由于这种关联，GH mRNA的降低可能会促进肥胖的发展。
