Hendricks S A, de Pablo F, Roth J
Endocrinology. 1984 Oct;115(4):1315-23. doi: 10.1210/endo-115-4-1315.
We studied the development of insulin binding to its receptor in chick embryos from days 2-18 of the 21-day incubation period. Using partially purified membrane preparations we found that insulin receptors on both brain and liver of day 18 embryos were typical insulin receptors by multiple criteria. Specific insulin binding to preparations of whole embryos was not detected on day 2, but was present by day 3. Insulin receptors were present on both heads and bodies of embryos by day 4. Binding to liver and brains increased with development between days 8 and 18; however, the patterns of increase in the two tissues were quite distinct. In liver, binding was low on day 8, but increased markedly by day 14 (P less than 0.01). Increases after day 14 were less impressive. In contrast, binding to brain preparations was relatively well established by day 8 and did not change significantly between days 8 and 14. An abrupt increase occurred between days 14 and 16 (P less than 0.01), and a second increase took place between days 16 and 18. We have previously shown that insulin is present in chick embryos before known pancreatic development. The current demonstration that insulin receptors are also present early in embryogenesis makes it possible that insulin may influence the embryo at early stages. In addition, the different patterns of increases in insulin binding in liver and brain during mid- to late development suggest complex and tissue-specific mechanisms of regulation.
我们研究了在21天孵化期的第2至18天鸡胚中胰岛素与其受体结合的发育情况。使用部分纯化的膜制剂，我们发现，根据多项标准，第18天胚胎的脑和肝上的胰岛素受体都是典型的胰岛素受体。在第2天未检测到全胚胎制剂上有特异性胰岛素结合，但在第3天出现了。到第4天，胚胎的头部和身体上都有胰岛素受体。在第8至18天之间，与肝和脑的结合随发育而增加；然而，这两种组织中结合增加的模式非常不同。在肝脏中，第8天结合较低，但到第14天显著增加（P小于0.01）。第14天之后的增加不太明显。相比之下，到第8天，与脑制剂的结合相对稳定，在第8至14天之间没有显著变化。在第14至16天之间出现了突然增加（P小于0.01），在第16至18天之间又出现了一次增加。我们之前已经表明，在已知胰腺发育之前，鸡胚中就存在胰岛素。目前关于胰岛素受体在胚胎发生早期也存在的证明使得胰岛素可能在早期阶段影响胚胎成为可能。此外，在发育中期至后期，肝脏和脑中胰岛素结合增加的不同模式表明存在复杂的组织特异性调节机制。
