Gallo-Payet N, Hugon J S
Endocrinology. 1984 May;114(5):1885-92. doi: 10.1210/endo-114-5-1885.
Isolated intestinal cells from adult mice possess a high concentration of insulin receptors. The binding capacity and the number of binding sites are higher in duodenum than in jejunum or ileum and in the upper part of the villus than in the crypts. The specific binding is, respectively, 11.8 +/- 1.0%, 9.1 +/- 4.0%, and 5.5 +/- 0.3%/mg . protein for duodenum, jejunum, and ileum. The number of high affinity sites per cell is, respectively, 11.0 X 10(3), 3 X 10(3), and 2.5 X 10(3). The number of low affinity sites per cell is, respectively, 11.0 X 10(4), 4.1 X 10(3), and 3.9 X 10(3). This specific binding increases to 15.9 +/- 0.9% after 24 h of fasting and to 24.5 +/- 2.2% mg protein after 48 h of fasting. This increase is due not only to an increment in the number of sites but also to alterations in affinity constants (K1, control, 0.380, 48-h fasting, 0.044 X 10(9) M-1; K2, control, 1.20, 48-h fasting; 2.61 X 10(7) M-1). The receptors are mainly located on the basolateral and internal membranes (P1, 9.4 +/- 0.7%/mg protein), but are also present on brush border membranes (P2, 2.6 +/- 1.1%/mg protein, P less than 0.01). After 24 h of organ culture, the specific binding is not modified in duodenal explants. Moreover, in the presence of insulin in the culture medium, the binding is decreased by 59%.
成年小鼠的分离肠细胞具有高浓度的胰岛素受体。十二指肠中胰岛素受体的结合能力和结合位点数量高于空肠或回肠，绒毛上部高于隐窝。十二指肠、空肠和回肠的特异性结合分别为11.8±1.0%、9.1±4.0%和5.5±0.3%/mg蛋白质。每个细胞的高亲和力位点数量分别为11.0×10³、3×10³和2.5×10³。每个细胞的低亲和力位点数量分别为11.0×10⁴、4.1×10³和3.9×10³。禁食24小时后，这种特异性结合增加到15.9±0.9%，禁食48小时后增加到24.5±2.2%/mg蛋白质。这种增加不仅是由于位点数量的增加，还由于亲和常数的改变（K1，对照，0.380，禁食48小时，0.044×10⁹M⁻¹；K2，对照，1.20，禁食48小时；2.61×10⁷M⁻¹）。受体主要位于基底外侧膜和内膜上（P1，9.4±0.7%/mg蛋白质），但也存在于刷状缘膜上（P2，2.6±1.1%/mg蛋白质，P<0.01）。器官培养24小时后，十二指肠外植体中的特异性结合未改变。此外，在培养基中存在胰岛素的情况下，结合减少了59%。
