Marino G, Zanghì A
Department of Veterinary Public Health, Messina 98168, Italy.
Anat Histol Embryol. 2013 Feb;42(1):1-8. doi: 10.1111/j.1439-0264.2012.01161.x. Epub 2012 May 28.
Activins and inhibins are regulatory proteins of the reproductive function. Inhibins antagonise the activin signalling at different levels and are responsible for the negative feedback in the regulation of the release of pituitary follicle stimulating hormone (FSH), which, in turn, is promoted by locally produced activins. In the canine ovary, both peptides are expressed by developing follicles and corpora lutea. Activins may play a stimulatory role in follicular development, promoting the aromatase function; inhibins modulate these processes and suppress the hyperplasic/neoplastic stimuli. Activins are required for ovulation and corpus luteum formation, while inhibins stimulate progesterone synthesis. The exclusive production of alpha-inhibin by granulosa cells allows the peptide to be used as marker to identify canine ovarian stromal tumours by immunohistochemistry. In the male, activins are powerful morphogenetic factors in the foetal testis. In the adult, they display a modulating action on spermatogenesis and Sertoli cell function. Inhibins, produced mainly by Leydig cells, promote testosterone secretion. Canine testicular tumours, such as Leydig, Sertoli and granulosa cell tumours (GCTs), may express inhibin subunits and produce high circulating levels of these glycoproteins. In the canine prostate, activins inhibit epithelium proliferation, antagonising androgen effects, but they are synthesised under androgenic stimulus.
激活素和抑制素是生殖功能的调节蛋白。抑制素在不同水平拮抗激活素信号，并负责垂体促卵泡激素（FSH）释放调节中的负反馈，而局部产生的激活素则促进FSH的释放。在犬卵巢中，这两种肽均由发育中的卵泡和黄体表达。激活素可能在卵泡发育中起刺激作用，促进芳香化酶功能；抑制素调节这些过程并抑制增生性/肿瘤性刺激。排卵和黄体形成需要激活素，而抑制素则刺激孕酮合成。颗粒细胞独家产生α-抑制素，使得该肽可作为通过免疫组织化学鉴定犬卵巢基质肿瘤的标志物。在雄性中，激活素是胎儿睾丸中强大的形态发生因子。在成年期，它们对精子发生和支持细胞功能具有调节作用。抑制素主要由睾丸间质细胞产生，促进睾酮分泌。犬睾丸肿瘤，如睾丸间质细胞瘤、支持细胞瘤和颗粒细胞瘤（GCT），可能表达抑制素亚基并产生高循环水平的这些糖蛋白。在犬前列腺中，激活素抑制上皮细胞增殖，拮抗雄激素作用，但它们是在雄激素刺激下合成的。
