Villanúa M A, Tresguerres J A, Esquifino A I
Departamentos de Fisiologia y Bioquímica, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
Chronobiol Int. 1988;5(4):337-43. doi: 10.3109/07420528809067779.
Prolactin is involved in the regulation of several endocrine functions. In this study, the possible influence of hyperprolactinemia on circadian corticosterone secretion has been investigated. Pituitary grafted male and female rats exhibited increased plasma PRL levels at 1000 when compared to sham-operated controls. This increase was only maintained over the 24 h period in grafted female rats but not in males, thus suggesting a different sex dependent modification of the regulatory mechanisms of prolactin. The corticosterone secretion pattern in sham operated male and female rats was similar to those described earlier but was altered by hyperprolactinemia according to the sex of the animal. There was a significant decrease in the total amount of corticosterone secreted in a 24 h period in grafted males as compared to control animals, whereas no significant differences were observed in grafted female rats as compared to controls. Grafted females showed a 4 h delay in the 24 h secretion rhythm as compared to control animals. These data suggest that pituitary transplant induced hyperprolactinemia, directly or through modifications in catecholamine turnover, is able to modify adrenal rhythmicity.
催乳素参与多种内分泌功能的调节。在本研究中，已对高催乳素血症对昼夜皮质酮分泌的可能影响进行了调查。与假手术对照组相比，垂体移植的雄性和雌性大鼠在1000时血浆PRL水平升高。这种升高仅在移植的雌性大鼠中在24小时内维持，而在雄性大鼠中则没有，因此表明催乳素调节机制存在不同的性别依赖性改变。假手术的雄性和雌性大鼠的皮质酮分泌模式与先前描述的相似，但根据动物的性别，高催乳素血症会改变这种模式。与对照动物相比，移植雄性大鼠在24小时内分泌的皮质酮总量显著减少，而与对照相比，移植雌性大鼠未观察到显著差异。与对照动物相比，移植雌性大鼠在24小时分泌节律上延迟了4小时。这些数据表明，垂体移植诱导的高催乳素血症，直接或通过儿茶酚胺代谢的改变，能够改变肾上腺节律。
