Baxter R C, Bryson J M, Turtle J R
Metabolism. 1981 Mar;30(3):211-6. doi: 10.1016/0026-0495(81)90143-8.
The effect of streptozotocin-induced diabetes (100 mg/kg) on lactogenic binding sites, measured by iodinated ovine prolactin (PRL) binding, has been studied in liver microsomal membranes from males and female rats. In females, specific binding was reduced in diabetes from 13% to 4.5% of total tracer, while in males specific binding increased from 0.5% to 2.5%. Similar results were obtained using iodinated human growth hormone as tracer, through overall binding was higher. Scatchard plots of binding curves in females showed that changes in binding were due to changes in receptor concentration, while affinity remained unchanged at 2 X 10(9) M-1. In diabetes, serum PRL and estradiol levels fell by 60% in males but showed no significant change in females, and could therefore not account for receptor changes. In contrast, mean testosterone levels fell in diabetic males from 9.0 to 3.9 nM, and rose in diabetic females from 2.1 to 5.8 nM. Estrogen treatment of male rats caused a marked induction of binding in nondiabetic animals, and a change from the male to the female response to diabetes. Testosterone treatment of nondiabetic females suppressed binding, although not to the male levels, and diabetes caused further suppression. These results are consistent with a role for testosterone in regulating PRL receptors in experimental diabetes, but suggest that other hormonal influences are also involved.
通过碘化羊催乳素（PRL）结合来测量链脲佐菌素诱导的糖尿病（100mg/kg）对雄性和雌性大鼠肝微粒体膜中催乳素结合位点的影响。在雌性大鼠中，糖尿病状态下特异性结合从总示踪剂的13%降至4.5%，而在雄性大鼠中，特异性结合从0.5%增加到2.5%。使用碘化人生长激素作为示踪剂也获得了类似结果，尽管总体结合率更高。雌性大鼠结合曲线的Scatchard图显示，结合变化是由于受体浓度的改变，而亲和力在2×10⁹M⁻¹时保持不变。在糖尿病状态下，雄性大鼠血清PRL和雌二醇水平下降60%，而雌性大鼠无显著变化，因此不能解释受体的变化。相反，糖尿病雄性大鼠的平均睾酮水平从9.0 nM降至3.9 nM，糖尿病雌性大鼠的平均睾酮水平从2.1 nM升至5.8 nM。对雄性大鼠进行雌激素处理可使非糖尿病动物的结合显著诱导，并使对糖尿病的反应从雄性转变为雌性。对非糖尿病雌性大鼠进行睾酮处理可抑制结合，尽管未达到雄性水平，而糖尿病会导致进一步抑制。这些结果与睾酮在实验性糖尿病中调节PRL受体的作用一致，但表明也涉及其他激素影响。
