Constans T, Chevalier B, Derouet M, Simon J
Station de Recherches Avicoles, Institut National de la Recherche Agronomique, Nouzilly, France.
Am J Physiol. 1991 Oct;261(4 Pt 2):R882-90. doi: 10.1152/ajpregu.1991.261.4.R882.
Insulin sensitivity and liver insulin receptor structure were studied in 5-wk-old ducks from two genera (Muscovy and Pekin). In the fasting state, both duck types were equally resistant to exogenous insulin compared with chicken. Despite the low potency of duck insulin, the number of insulin receptors was lower in Muscovy duck and similar in Pekin duck and chicken liver membranes. After 125I-insulin cross-linking, the size of the alpha-subunit of the receptors from the three species was 135,000. Wheat germ agglutinin-purified receptors from the three species were contaminated by an active and unusual adenosinetriphosphatase (ATPase) contaminant (highest activity in Muscovy duck). Sequential purification of solubilized receptor from both duck types on lentil and then wheat germ agglutinin lectins led to a fraction of receptors very poor in ATPase activity that exhibited a beta-subunit size (95,000) and tyrosine kinase activity similar to those of ATPase-free chicken insulin receptors. Therefore the ducks from the two genera exhibit an alpha-beta-structure for liver insulin receptors and a clear difference in the number of liver insulin receptors. Their sensitivity to insulin is, however, similarly decreased compared with chicken.
对来自两个属（番鸭和北京鸭）的5周龄鸭子的胰岛素敏感性和肝脏胰岛素受体结构进行了研究。在禁食状态下，与鸡相比，两种鸭子对外源胰岛素的抵抗性相同。尽管鸭胰岛素的效力较低，但番鸭肝脏膜中的胰岛素受体数量较少，北京鸭和鸡肝脏膜中的胰岛素受体数量相似。用125I-胰岛素交联后，三种物种受体的α亚基大小均为135,000。三种物种经麦胚凝集素纯化的受体均被一种活性且异常的腺苷三磷酸酶（ATPase）污染物污染（番鸭中活性最高）。在扁豆凝集素和麦胚凝集素上对两种鸭子的可溶性受体进行连续纯化，得到了一部分ATPase活性极低的受体，其β亚基大小（95,000）和酪氨酸激酶活性与无ATPase的鸡胰岛素受体相似。因此，两个属的鸭子肝脏胰岛素受体均呈现α-β结构，且肝脏胰岛素受体数量存在明显差异。然而，与鸡相比，它们对胰岛素的敏感性同样降低。
