Smith R D, Hilf R, Senior A E
Cancer Res. 1976 Oct;36(10):3726-31.
Specific binding of radioactively labeled prolactin was determined in membrane preparations from mammary glands and livers of rats during pregnancy and lactation. Prolactin binding to mammary gland increased throughout late pregnancy and early lactation, reached a maximum on Day 11 of lactation, and then declined. Maximum prolactin binding to liver membrane preparations was observed during late pregnancy and declined throughout lactation. Estradiol benzoate (20 mug/day), administered on Days 5 to 10 of lactation, reduced prolactin binding to mammary gland by 55%, increased binding to liver 2-fold, and reduced litter weight gain by 25%. Prolactin binding to 7,12-dimethylbenz(a)anthracene-induced mammary tumors was 3 times higher than that observed in lactating mammary gland. Administration of prolactin enhanced tumor growth but decreased specific prolactin binding to tumors. Lergotrile mesylate inhibited and estradiol benzoate (2 mug/day) enhanced tumor growth, but neither treatment affected prolactin binding to tumor membrane preparations. In contrast, higher doses of estradiol benzoate (20 mug/day) inhibited tumor growth and reduced prolactin binding. Prolactin binding varied widely within all groups of mammary tumors and was not clearly related to growth response or to altered circulating estrogen and/or prolactin levels. Hormone dependence in this animal tumor model is complex and may not be predicted on the basis of prolactin-binding capacity alone.
在妊娠和哺乳期大鼠的乳腺和肝脏膜制剂中测定了放射性标记催乳素的特异性结合。催乳素与乳腺的结合在妊娠后期和哺乳期早期持续增加，在哺乳期第11天达到最大值，然后下降。在妊娠后期观察到催乳素与肝膜制剂的结合最大值，在整个哺乳期下降。在哺乳期第5至10天给予苯甲酸雌二醇（20微克/天），可使催乳素与乳腺的结合减少55%，使与肝脏的结合增加2倍，并使窝仔体重增加减少25%。催乳素与7,12-二甲基苯并(a)蒽诱导的乳腺肿瘤的结合比在泌乳乳腺中观察到的高3倍。给予催乳素可促进肿瘤生长，但降低催乳素与肿瘤的特异性结合。甲磺酸麦角腈抑制肿瘤生长，苯甲酸雌二醇（2微克/天）促进肿瘤生长，但两种处理均不影响催乳素与肿瘤膜制剂的结合。相反，更高剂量的苯甲酸雌二醇（20微克/天）抑制肿瘤生长并降低催乳素结合。在所有乳腺肿瘤组中，催乳素结合差异很大，与生长反应或循环雌激素和/或催乳素水平的改变没有明显关系。在这个动物肿瘤模型中，激素依赖性很复杂，可能不能仅根据催乳素结合能力来预测。
