Bhagat L, Duraiswami S
Department of Zoology, University of Delhi, India.
J Pineal Res. 1992 Sep;13(2):72-9. doi: 10.1111/j.1600-079x.1992.tb00057.x.
In an attempt to define the antigonadotropic activity associated with the protein/peptide extracts of ovine pineals, melatonin- and steroid-free fractions obtained after subjecting crude ovine pineal acetone powder to soft gel chromatography were tested in three bioassay systems: (1) the conventional compensatory ovarian hypertrophy inhibition assay in rats, (2) the coupled bioassay in immature mice that enables one to distinguish factors acting at the level of the pituitary from those acting at the gonadal level, and (3) the classical in vitro pituitary cell culture assay for inhibin. The large molecular weight fraction, referred to as PI, behaved like a classical antigonadotropin as it suppressed compensatory ovarian hypertrophy following unilateral ovariectomy. Further, it not only lowered the basal and gonadotropin releasing hormone (GnRH)-stimulated release of follicle stimulating hormone (FSH) by the cultured pituitary cells, but also inhibited the human chorionic gonadotropin (hCG)-induced uterine weight gain in the coupled assay, thus acting like inhibin in these two assay systems. In addition, it showed immunological cross-reactivity with ovine testicular inhibin. The present results strongly support the view that inhibin-like activity may be the major player in what has so far been referred to as antigonadotropic activity.
为了确定与绵羊松果体蛋白质/肽提取物相关的抗促性腺活性，将粗制绵羊松果体丙酮粉进行软凝胶色谱分离后得到的无褪黑素和无类固醇的组分，在三种生物测定系统中进行了测试：（1）大鼠常规代偿性卵巢肥大抑制试验；（2）未成熟小鼠的联合生物测定，该测定能够区分作用于垂体水平的因子和作用于性腺水平的因子；（3）经典的垂体细胞体外抑制素培养测定。称为PI的大分子组分表现得像一种经典的抗促性腺激素，因为它在单侧卵巢切除术后抑制了代偿性卵巢肥大。此外，它不仅降低了培养的垂体细胞的基础促性腺激素释放以及促性腺激素释放激素（GnRH）刺激的促卵泡激素（FSH）释放，而且在联合测定中还抑制了人绒毛膜促性腺激素（hCG）诱导的子宫重量增加，因此在这两种测定系统中其作用类似于抑制素。此外，它与绵羊睾丸抑制素表现出免疫交叉反应性。目前的结果有力地支持了这样一种观点，即抑制素样活性可能是迄今为止被称为抗促性腺活性的主要因素。
