Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Poult Sci. 2012 Jan;91(1):161-74. doi: 10.3382/ps.2011-01439.
Decreasing fertility in aging domestic roosters is a well-known phenomenon. Aging is manifested by a decrease in plasma testosterone level, testis function, and spermatogenesis, resulting in a low level of fertility. The roles of vasoactive intestinal peptide (VIP) and testicular inhibin in this aging process are not clear. The effects of active immunization against VIP, inhibin, or the combination of both hormones on the reproduction of aging White Leghorn (WL) roosters were assayed. In experiment 1a, 60 White Leghorn roosters (67 wk of age) were divided into 4 groups (n = 15/group). The first group was actively immunized against VIP, the second against inhibin, the third against VIP and inhibin, and the fourth served as a control. Active immunization against VIP decreased semen quality parameters, plasma steroid levels, and gene expression of gonadotropin-releasing hormone-I (GnRH-I), follicle-stimulating hormone (FSH), luteinizing hormone (LH), LH receptor, VIP, and prolactin (Prl). Immunization against inhibin increased some of the semen quality parameters and FSH mRNA gene expression but decreased inhibin gene expression. In experiment 1b, at 94 wk of age, we took the actively immunized against VIP group and the control group and divided them into 2 subgroups (n = 7 or 8): the first group was injected with 1 mg of ovine Prl (oPrl) daily for 7 d, and the second group served as a control. Administration of oPrl to previously VIP-immunized birds significantly elevated semen quality parameters. We suggest that VIP, Prl, and inhibin have an important effect on the reproductive axis in aging roosters. Active immunization against VIP-depressed reproductive activity and Prl administration restored their reproduction, indicating that both VIP and Prl are essential for reproduction in aging roosters. Immunization against inhibin improved FSH mRNA gene expression, suggesting a negative role of inhibin on FSH secretion in aging roosters. Not all semen quality parameters increased significantly after immunization against inhibin, even though FSH mRNA gene expression increased, suggesting interference in testicular function in aging roosters.
随着年龄的增长，家养公鸡的繁殖能力下降是一种众所周知的现象。衰老表现为血浆睾丸酮水平、睾丸功能和精子发生减少，导致生育能力低下。血管活性肠肽（VIP）和睾丸抑制素在这一衰老过程中的作用尚不清楚。本研究检测了针对 VIP、抑制素或这两种激素联合主动免疫对衰老白来航鸡（WL）公鸡繁殖性能的影响。在实验 1a 中，将 60 只白来航公鸡（67 周龄）分为 4 组（每组 15 只）。第一组公鸡接受 VIP 主动免疫，第二组公鸡接受抑制素主动免疫，第三组公鸡接受 VIP 和抑制素主动免疫，第四组公鸡作为对照组。VIP 主动免疫降低了精液质量参数、血浆类固醇水平和促性腺激素释放激素-I（GnRH-I）、促卵泡激素（FSH）、黄体生成素（LH）、LH 受体、VIP 和催乳素（Prl）的基因表达。抑制素主动免疫增加了一些精液质量参数和 FSH mRNA 基因表达，但降低了抑制素基因表达。在实验 1b 中，在 94 周龄时，我们从接受 VIP 主动免疫的公鸡和对照组公鸡中各取 7 或 8 只分为 2 个亚组：第一组每天注射 1mg 羊催乳素（oPrl）连续 7d，第二组作为对照组。先前接受 VIP 免疫的公鸡给予 oPrl 后，精液质量参数显著升高。本研究结果表明，VIP、Prl 和抑制素对老龄公鸡生殖轴有重要作用。VIP 免疫抑制公鸡的生殖活性，给予 Prl 可恢复其生殖能力，表明 VIP 和 Prl 都是老龄公鸡生殖所必需的。抑制素免疫提高了 FSH mRNA 基因表达，提示抑制素对老龄公鸡 FSH 分泌有负调控作用。尽管 FSH mRNA 基因表达增加，但抑制素免疫后并非所有精液质量参数都显著增加，提示老龄公鸡睾丸功能受到干扰。
