Campbell K L, Landefeld T D, Midgley A R
Proc Natl Acad Sci U S A. 1980 Aug;77(8):4793-7. doi: 10.1073/pnas.77.8.4793.
The question of whether the two subunits of the glycoprotein hormone human chorionic gonadotropin (hCG) are handled separately or as a unit by target cells was addressed by using a dual-labeling procedure. The individual alpha and beta subunits of hCG were labeled with 131I or 125I, recombined, chromatographed, and injected intravenously into hormonally primed immature rats. The ovaries of these rats contained large numbers of antral follicles, the granulosa cells of which possess high concentrations of receptor for hCG. Comparisons of the distribution of the different radioisotopic labels in various tissues over time indicated the activity associated with the beta subunit was preferentially retained by the ovarian granulosa cells in a hormone-specific manner, while the activity associated with the alpha subunit was preferentially lost. This contrasted with other tissues, including other ovarian cells with receptor for hCG, in which both radiolabels were either handled nondifferentially or handled differentially in a hormonally nonspecific manner.
利用双标记程序探讨了糖蛋白激素人绒毛膜促性腺激素（hCG）的两个亚基是被靶细胞分别处理还是作为一个整体处理的问题。hCG的α和β亚基分别用¹³¹I或¹²⁵I标记，重新组合、层析，然后静脉注射到经激素预处理的未成熟大鼠体内。这些大鼠的卵巢含有大量的窦状卵泡，其颗粒细胞具有高浓度的hCG受体。随着时间的推移，对不同放射性同位素标记在各种组织中的分布进行比较，结果表明，与β亚基相关的活性以激素特异性方式被卵巢颗粒细胞优先保留，而与α亚基相关的活性则优先丧失。这与其他组织形成对比，包括其他具有hCG受体的卵巢细胞，在这些组织中，两种放射性标记要么被无差异处理，要么以激素非特异性方式被差异处理。
