Dunbar J C, Wider M, Dixon S, Tobkin M
Proc Soc Exp Biol Med. 1987 Mar;184(3):320-5. doi: 10.3181/00379727-184-42486.
We studied glucagon and insulin binding to isolated hepatocyte receptors in Wistar-Furth (WF) and Sprague-Dawley (SD) rats, using 125I-labeled hormones. Hepatocytes from WF rats bound more glucagon than hepatocytes from SD rats. There were no differences in insulin binding. These observations prompted us to investigate other strain differences. Fasting and nonfasting serum glucose, glucagon, insulin, and growth hormone were measured. WF animals had a lower fasting glucose and higher fasting glucagon than SD animals, while SD rats had higher nonfasting insulin levels and a higher hepatic glycogen content. Total hepatic glucose production in response to glucagon (10(-8) M) was greater in WF than in SD rats, while glucagon-stimulated gluconeogenesis from alanine was the same in the two groups of animals. We concluded that the decreased glucagon binding does not play a significant role in the maintenance of serum glucose or in the gluconeogenetic response glucagon, and that neither these responses nor the serum glucagon levels appears to be correlated with the number of glucagon receptors. We conclude further that different animal strains of the same species may differ in their biologic responses.
我们使用125I标记的激素，研究了Wistar-Furth（WF）大鼠和Sprague-Dawley（SD）大鼠分离的肝细胞受体对胰高血糖素和胰岛素的结合情况。WF大鼠的肝细胞比SD大鼠的肝细胞结合更多的胰高血糖素。胰岛素结合方面没有差异。这些观察结果促使我们研究其他品系差异。测量了禁食和非禁食状态下的血清葡萄糖、胰高血糖素、胰岛素和生长激素。WF动物的空腹血糖较低，空腹胰高血糖素较高，而SD大鼠的非空腹胰岛素水平较高，肝糖原含量较高。WF大鼠对胰高血糖素（10(-8) M）的肝脏葡萄糖总生成量比SD大鼠更大，而两组动物中胰高血糖素刺激的丙氨酸糖异生作用相同。我们得出结论，胰高血糖素结合减少在维持血糖或胰高血糖素的糖异生反应中不起重要作用，并且这些反应和血清胰高血糖素水平似乎都与胰高血糖素受体数量无关。我们进一步得出结论，同一物种的不同动物品系在生物学反应上可能存在差异。
