Köves K, Molnár J, Kántor O, Görcs T J, Lakatos A, Arimura A
Second Department of Anatomy, Semmelweis University Medical School, Budapest, Hungary.
Ann N Y Acad Sci. 1996 Dec 26;805:648-54. doi: 10.1111/j.1749-6632.1996.tb17535.x.
The presence of PACAP was revealed in the anterior pituitary with RIA, HPLC, and with the demonstration of its mRNA. The level of PACAP mRNA in the anterior pituitary is the highest during the proestrous LH surge. In our immunohistochemical studies we were able to demonstrate PACAP immunoreactive cells in the anterior pituitary. The shape and the distribution of PACAP immunoreactive cells were very similar to that of the gonadotropes; however, the number of PACAP cells was less than that of LH cells. Additionally, another PACAP-positive cell population with small diameter appeared in the proestrous stage, during pregnancy and lactation. Double labeling revealed that the major part of large PACAP cells exhibited LH immunoreactivity and those with a small diameter contained PRL. It is not clear whether the pituitary- or the hypothalamic-born PACAP, or both, influence pituitary LH and PRL secretion. I.c.v. administration of PACAP just prior to the critical period in the proestrous stage inhibited the expected ovulation and blocked the proestrus LH and PRL surge, although i.v. administration of PACAP had no effect. PACAP antiserum did not interfere with ovulation when i.c.v. or i.v. injection was used. Our results support the view that PACAP has a role in the control of LH and PRL secretion during the estrous cycle, pregnancy, and lactation. The inhibitory effect of PACAP on ovulation is mediated through the hypothalamus.
通过放射免疫分析(RIA)、高效液相色谱法(HPLC)以及对其信使核糖核酸(mRNA)的检测,发现垂体前叶存在垂体腺苷酸环化酶激活肽(PACAP)。在动情前期促黄体生成素(LH)峰期间,垂体前叶中PACAP mRNA的水平最高。在我们的免疫组织化学研究中,能够在垂体前叶中证实存在PACAP免疫反应性细胞。PACAP免疫反应性细胞的形态和分布与促性腺激素细胞非常相似;然而,PACAP细胞的数量少于LH细胞。此外,在动情前期、妊娠和哺乳期出现了另一群直径较小的PACAP阳性细胞。双重标记显示,大部分大的PACAP细胞表现出LH免疫反应性,而那些直径小的细胞含有催乳素(PRL)。尚不清楚是垂体来源还是下丘脑来源的PACAP,或者两者都对垂体LH和PRL分泌有影响。在动情前期关键期之前经脑室内(i.c.v.)注射PACAP可抑制预期的排卵,并阻断动情前期LH和PRL峰,尽管静脉内(i.v.)注射PACAP没有效果。当采用脑室内或静脉内注射时,PACAP抗血清不干扰排卵。我们的结果支持这样一种观点,即PACAP在发情周期、妊娠和哺乳期对LH和PRL分泌的控制中起作用。PACAP对排卵的抑制作用是通过下丘脑介导的。