Szabó E, Nemeskéri A, Arimura A, Köves K
Department of Human Morphology and Developmental Biology, Faculty of Medicine, Semmelweis University, Tuzoltó u. 58. H-1094 Budapest, Hungary.
Regul Pept. 2004 Dec 15;123(1-3):139-45. doi: 10.1016/j.regpep.2004.04.021.
We have previously demonstrated that pituitary adenylate cyclase activating polypeptide (PACAP) can be released from cultured rat anterior pituitary cells and when added to the medium in physiological concentration it releases LH from individual gonadotropes. In the present work, we studied whether the release of PACAP and the responsiveness of LH cells to PACAP depend on the gender, on the time of day when the animals were sacrificed, and in females on the stage of the estrous cycle. Anterior pituitary cells were cultured on nitrocellulose membrane. We found that the number of PACAP releasing cells was higher in proestrous than in diestrous female or in male rats and their number was always higher in the evening than at the other times. The effect of PACAP on LH cells was stimulatory in the morning of proestrus and diestrus. In proestrous rats, PACAP did not influence LH release in the afternoon or the evening, but in diestrous rats it decreased it in the afternoon and the evening. In males, there was a decrease of LH due to PACAP treatment at 10 and 20 h; however, PACAP did not influence LH at 16 h. It was concluded that in vivo PACAP might be involved in the circadian and episodic release of LH at pituitary level.
我们之前已经证明，垂体腺苷酸环化酶激活多肽（PACAP）可从培养的大鼠垂体前叶细胞中释放出来，当以生理浓度添加到培养基中时，它能从单个促性腺激素细胞中释放促黄体生成素（LH）。在本研究中，我们探讨了PACAP的释放以及LH细胞对PACAP的反应性是否取决于性别、动物处死的时间，以及雌性动物的发情周期阶段。垂体前叶细胞培养于硝酸纤维素膜上。我们发现，动情前期雌性大鼠中释放PACAP的细胞数量高于动情间期雌性大鼠或雄性大鼠，且其数量在傍晚时总是高于其他时间。PACAP对LH细胞的作用在动情前期和动情间期的早晨具有刺激作用。在动情前期大鼠中，PACAP在下午或傍晚不影响LH释放，但在动情间期大鼠中，它在下午和傍晚降低LH释放。在雄性大鼠中，在10小时和20小时给予PACAP处理会导致LH减少；然而，PACAP在16小时时不影响LH。研究得出结论，在体内，PACAP可能参与了垂体水平LH的昼夜节律性和阵发性释放。
