Chao C C, Malven P V
Peptides. 1987 Mar-Apr;8(2):361-6. doi: 10.1016/0196-9781(87)90112-4.
The anterior lobe (AL) of the bovine pituitary contained and released, during in vitro culture, a form of immunoreactive dynorphin-A (ir-DYN-A) larger than that occurring in neural tissue. Bovine AL tissue from intact females contained less ir-DYN-A than did AL tissue from castrated males. Enzymatically dispersed AL cells contained and released ir-DYN-A in vitro. Preincubation of dispersed AL cells for 18 hr, rather than 1.5 hr, increased the content and release of ir-DYN-A as well as LH. Addition of gonadotropin-releasing hormone (GnRH) to tissue slices or dispersed cells stimulated release of LH, but in contrast to published observations from rat AL, GnRH had no effect on release of ir-DYN-A. Addition of estradiol-17 beta, with or without progesterone, increased release of ir-DYN-A but not LH during 2-hr cultures. In summary, bovine AL contains and releases in vitro a large molecular weight form of ir-DYN-A. Although this ir-DYN-A was not coreleased with LH, a reproductive role was suggested by in vivo and in vitro effects of gonadal hormones on ir-DYN-A in the bovine anterior pituitary.
牛垂体前叶在体外培养期间含有并释放一种免疫反应性强啡肽 -A（ir-DYN-A），其形式比神经组织中出现的更大。完整雌性牛的垂体前叶组织所含的 ir-DYN-A 比去势雄性的垂体前叶组织少。经酶分散的垂体前叶细胞在体外含有并释放 ir-DYN-A。将分散的垂体前叶细胞预孵育18小时而非1.5小时，会增加 ir-DYN-A 以及促黄体生成素（LH）的含量和释放。向组织切片或分散细胞中添加促性腺激素释放激素（GnRH）可刺激 LH 的释放，但与大鼠垂体前叶已发表的观察结果相反，GnRH 对 ir-DYN-A 的释放没有影响。在2小时培养期间，添加17β-雌二醇，无论有无孕酮，都会增加 ir-DYN-A 的释放，但不会增加 LH 的释放。总之，牛垂体前叶在体外含有并释放一种大分子形式的 ir-DYN-A。尽管这种 ir-DYN-A 不与 LH 共同释放，但性腺激素对牛垂体前叶中 ir-DYN-A 的体内和体外作用表明其具有生殖作用。
