Esquifino A I, Villanua M A, Agrasal C, Reiter R J, Tresguerres J A
Departamento de Bioquimica, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
J Endocrinol Invest. 1989 Mar;12(3):171-6. doi: 10.1007/BF03349954.
Melatonin influences prolactin (PRL) secretion through unknown mechanisms. This work was undertaken to study the effects of melatonin administration of PRL secretion in pituitary-grafted female rats. Melatonin administration resulted in a marked and rapid decrease of previously high plasma PRL levels in pituitary-grafted rats. Luteinizing hormone releasing hormone (LHRH) administration resulted in a marked decrease of plasma PRL levels in both sham-operated and grafted animals given saline whereas a statistically significant increase was observed in grafted, melatonin-treated rats. Estradiol benzoate administration caused an increase in plasma PRL levels of greater magnitude in the afternoon than in the morning in sham-operated animals given saline whereas in grafted animals no response to estradiol benzoate was detected. Melatonin increased the plasma PRL response to estradiol benzoate in sham-operated rats as compared to vehicle-treated animals. A normalization of PRL response to estradiol benzoate was shown in melatonin-treated, pituitary grafted rats. While the suppressive effects of melatonin in plasma PRL levels of pituitary-grafted animals is substantial the mechanism of this inhibition remains unknown.
褪黑素通过未知机制影响催乳素（PRL）的分泌。本研究旨在探讨褪黑素对垂体移植雌性大鼠PRL分泌的影响。给予褪黑素后，垂体移植大鼠先前较高的血浆PRL水平显著且迅速下降。给予促黄体生成素释放激素（LHRH）后，假手术组和接受生理盐水处理的移植动物的血浆PRL水平显著下降，而在接受褪黑素处理的移植大鼠中观察到统计学上显著的增加。给予苯甲酸雌二醇后，接受生理盐水处理的假手术动物下午血浆PRL水平的升高幅度大于上午，而在移植动物中未检测到对苯甲酸雌二醇的反应。与接受载体处理的动物相比，褪黑素增加了假手术大鼠对苯甲酸雌二醇的血浆PRL反应。在接受褪黑素处理的垂体移植大鼠中，显示出对苯甲酸雌二醇的PRL反应正常化。虽然褪黑素对垂体移植动物血浆PRL水平的抑制作用显著，但其抑制机制仍不清楚。
