Roth H P, Kirchgessner M
Institute of Nutrition Physiology, Technical University Munich, Freising-Weihenstephan, Germany.
Horm Metab Res. 1994 Sep;26(9):404-8. doi: 10.1055/s-2007-1001718.
The study described here investigates the influence of a specific alimentary Zn deficiency on the concentration of growth hormone (GH), insulin-like growth factor I (IGF-I) and insulin in the serum of force-fed rats. For this purpose 24 male Sprague-Dawley rats with an average bodyweight of 108 g were divided into 2 groups of 12 animals each. The Zn-deficient group and the control group received for 12 days a semi-synthetic casein diet with a Zn content of 1.3 and 25 ppm respectively. In order to prevent the reduced feed intake which occurs in Zn deficiency and the associated energy and protein shortage from interfering with the experimental parameters, all animals were fed 4 times daily by gastric tube. This made it possible to supply all animals with adequate-nutrients and to synchronise the feed intake exactly. After 12 days the depleted rats were in a severe state of Zn deficiency, as demonstrated by the reduction of Zn in the serum and the femur by 62% and 44% respectively and the 70% lower serum activity of alkaline phosphatase. In the Zn-deficient rats the concentration of GH in the serum was significantly increased by 78%, while IGF-1 and insulin were significantly reduced by 28% and 25% respectively. It is thought that the growth depression observed in the Zn-deficient rats in this study despite their identical feed intake is probably due to a reduced concentration of IGF-I and insulin and that the biological activity or the binding of GH to receptors is impaired in specific alimentary Zn deficiency.
本文所述的研究探讨了特定膳食锌缺乏对强制喂食大鼠血清中生长激素（GH）、胰岛素样生长因子I（IGF-I）和胰岛素浓度的影响。为此，将24只平均体重为108 g的雄性斯普拉格-道利大鼠分为两组，每组12只。缺锌组和对照组分别接受了12天的半合成酪蛋白饮食，锌含量分别为1.3 ppm和25 ppm。为了防止锌缺乏时出现的采食量减少以及相关的能量和蛋白质短缺干扰实验参数，所有动物每天通过胃管喂食4次。这使得能够为所有动物提供充足的营养，并精确同步采食量。12天后，缺锌大鼠处于严重的锌缺乏状态，血清和股骨中的锌分别减少了62%和44%，血清碱性磷酸酶活性降低了70%，这证明了这一点。在缺锌大鼠中，血清中GH的浓度显著增加了78%，而IGF-1和胰岛素分别显著降低了28%和25%。据认为，本研究中缺锌大鼠尽管采食量相同但仍出现生长抑制，可能是由于IGF-I和胰岛素浓度降低，并且在特定膳食锌缺乏时，GH与受体的生物活性或结合受到损害。
