Turyn D, Dellacha J M
Endocrinology. 1978 Oct;103(4):1190-5. doi: 10.1210/endo-103-4-1190.
The specific uptake by rat liver of human (hGH) and bovine (bGH) GHs labeled with 125I was studied by an in vivo procedure. A significant reduction of the uptake was observed when labeled hormones were injected together with different amounts of the corresponding native GH. This reduction was dose dependent, and the concentration of native hormone that prevents 50% of the liver uptake of the labeled hormone was close to 12 microgram/100 g BW. In normal rats, only native hGH or bGH significantly decreased the liver uptake of [125I]iodo-bGH, while bovine PRL (oPRL) or heat-denatured bGH were inactive. The highest inhibition of the uptake of [125I]iodo-hGH by rat liver was obtained when this labeled hormone was injected either together with hGH or with bGH plus oPRL while partial displacement was observed with bGH or oPRL. These data suggest that hGH binds to both somatotropic and lactogenic sites in the liver of normal rats. In hypophysectomized animals, only the somatogenic binding sites could be detected.
采用体内实验方法研究了用¹²⁵I标记的人生长激素（hGH）和牛生长激素（bGH）被大鼠肝脏的特异性摄取情况。当标记激素与不同量的相应天然生长激素一起注射时，观察到摄取量显著降低。这种降低呈剂量依赖性，阻止50%标记激素肝脏摄取的天然激素浓度接近12微克/100克体重。在正常大鼠中，只有天然hGH或bGH能显著降低[¹²⁵I]碘代-bGH的肝脏摄取量，而牛催乳素（oPRL）或热变性bGH则无活性。当[¹²⁵I]碘代-hGH与hGH或与bGH加oPRL一起注射时，大鼠肝脏对其摄取的抑制作用最强，而单独注射bGH或oPRL时则观察到部分置换现象。这些数据表明，hGH在正常大鼠肝脏中与生长激素和催乳激素位点均有结合。在垂体切除的动物中，只能检测到生长激素结合位点。
