Russell S H, Small C J, Stanley S A, Franks S, Ghatei M A, Bloom S R
Imperial College School of Medicine, Endocrine Unit, Hammersmith Hospital, Du Cane Road, London W12 ONN, UK.
J Neuroendocrinol. 2001 Mar;13(3):296-301. doi: 10.1046/j.1365-2826.2001.00632.x.
The adipocyte derived hormone leptin has been implicated as an important nutritional signal to the reproductive system, but the role of other adipocyte related cytokines is not clear. Tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 are present in adipose tissue and released into the circulation where plasma levels correlate positively with body mass index and body fat mass. These cytokines could play a role in signalling nutritional status to the hypothalamic-pituitary-gonadal axis. We investigated the effects of TNF-alpha and IL-6 on basal and luteinizing hormone releasing hormone (LHRH) stimulated luteineizing hormone (LH) release from cultured anterior pituitary cells, harvested from either proestrus female or male Wistar rats. We examined the effects of TNF-alpha and IL-6 on LHRH release from hypothalamic explants harvested from proestrus female and male rats in vitro. IL-6 significantly suppressed LHRH stimulated LH release from male dispersed pituitaries throughout the dose range, but did not influence basal LH release. IL-6 had no effect on basal or LHRH stimulated LH release in dispersed pituitaries from proestrus females. By contrast, TNF-alpha significantly suppressed LHRH stimulated LH release in dispersed pituitaries from proestrus female rats in a dose responsive manner, but did not influence basal LH release. TNF-alpha had no effect on basal or LHRH stimulated LH release in dispersed pituitaries from male rats. TNF-alpha and IL-6 had no effect on LHRH release from male hypothalamic explants in vitro. TNF-alpha and IL-6 had no effect on LHRH release from proestrus female hypothalamic explants in vitro. TNF-alpha and IL-6 have differential effects in dispersed pituitaries harvested from males and proestrus female rats. TNF-alpha and IL-6 may be important in mediating some of the nutritional effects on the reproductive axis by acting at the level of the anterior pituitary rather than the hypothalamus.
脂肪细胞衍生的激素瘦素被认为是向生殖系统传递重要营养信号的物质，但其他与脂肪细胞相关的细胞因子的作用尚不清楚。肿瘤坏死因子-α（TNF-α）和白细胞介素（IL）-6存在于脂肪组织中，并释放到循环系统中，血浆水平与体重指数和体脂量呈正相关。这些细胞因子可能在向下丘脑-垂体-性腺轴传递营养状态信号方面发挥作用。我们研究了TNF-α和IL-6对从动情前期雌性或雄性Wistar大鼠采集的培养垂体前叶细胞基础促黄体生成素释放激素（LHRH）刺激的促黄体生成素（LH）释放的影响。我们研究了TNF-α和IL-6对体外从动情前期雌性和雄性大鼠采集的下丘脑外植体中LHRH释放的影响。在整个剂量范围内，IL-6显著抑制雄性分散垂体中LHRH刺激的LH释放，但不影响基础LH释放。IL-6对动情前期雌性大鼠分散垂体中的基础或LHRH刺激的LH释放没有影响。相比之下，TNF-α以剂量反应方式显著抑制动情前期雌性大鼠分散垂体中LHRH刺激的LH释放，但不影响基础LH释放。TNF-α对雄性大鼠分散垂体中的基础或LHRH刺激的LH释放没有影响。TNF-α和IL-6对体外雄性下丘脑外植体中的LHRH释放没有影响。TNF-α和IL-6对体外动情前期雌性下丘脑外植体中的LHRH释放没有影响。TNF-α和IL-6对从雄性和动情前期雌性大鼠采集的分散垂体有不同的作用。TNF-α和IL-6可能通过作用于垂体前叶而非下丘脑水平，在介导对生殖轴的一些营养作用方面很重要。
