Wrathall J H, Knight P G
School of Animal and Microbial Sciences, University of Reading, Whiteknights, UK.
J Endocrinol. 1995 Jun;145(3):491-500. doi: 10.1677/joe.0.1450491.
Primary monolayer cultures of bovine theca cells isolated from pooled ovarian follicles (3-10 mm diameter) were used to examine the effects of various granulosa cell-derived substances on basal and luteinizing hormone (LH)-induced androgen and progesterone secretion. After an overnight pretreatment period, cells were incubated with a range of treatments including LH, oestradiol-17 beta, inhibin, activin and follistatin. Media were collected after 48 h and assessment of androstenedione and progesterone secretion made by radioimmunoassay. Addition of LH (5-50 ng/ml) to the cells resulted in a dose-dependent stimulation of both androstenedione (2.5- to 3-fold rise; P < 0.01) and progesterone (approximately 1.6-fold rise; P < 0.001) production. Secretion of androstenedione was also raised (up to 5-fold; P < 0.001) by addition of oestradiol-17 beta (0.3-300 ng/ml), whilst levels of the androgen in the presence of both LH (20 ng/ml) and oestradiol (300 ng/ml) were up to 12-fold higher (P < 0.001) than control values. In contrast, oestradiol treatment inhibited by up to 50% both basal (P < 0.001) and LH-stimulated (P < 0.001) secretion of progesterone. Exposure of cells to purified bovine inhibin (5-125 ng/ml) consistently raised androstenedione secretion by up to 42% over basal levels (P < 0.001). Inhibin also enhanced both LH-stimulated (approximately 35%; P < 0.001) and oestradiol-stimulated (approximately 20%; P < 0.05) secretion of androstenedione. In direct contrast, treatment of theca cells with human recombinant activin-A (1-50 ng/ml) inhibited both LH-stimulated (approximately 50%; P < 0.001) and oestradiol-stimulated (approximately 30%; P < 0.005) androstenedione secretion. Activin also reversed the positive effect of inhibin on basal (P < 0.01), LH-stimulated (P < 0.001) and oestradiol-stimulated (P < 0.001) androstenedione secretion, though activin alone did not affect basal steroid output. Simultaneous addition of human recombinant follistatin reversed the inhibitory effects of activin on LH- and oestradiol-induced androstenedione secretion but did not modify the effects of inhibin. Follistatin alone did not alter either basal or LH-stimulated androstenedione output. Neither basal nor LH-stimulated secretion of progesterone were consistently affected by inhibin, activin or follistatin. As well as confirming the stimulatory effects of both LH and oestradiol on bovine thecal cell androgen production, these observations are indicative of opposing intrafollicular paracrine roles for granulosa cell-derived inhibin and activin in modulating thecal cell responses to gonadotrophins and steroids in the bovine ovary.(ABSTRACT TRUNCATED AT 400 WORDS)
从多个卵巢卵泡（直径3 - 10毫米）中分离出的牛卵泡膜细胞原代单层培养物，用于检测各种颗粒细胞衍生物质对基础及促黄体生成素（LH）诱导的雄激素和孕酮分泌的影响。经过一夜的预处理期后，将细胞与一系列处理因素共同孵育，这些因素包括LH、雌二醇 - 17β、抑制素、激活素和卵泡抑素。48小时后收集培养基，通过放射免疫测定法评估雄烯二酮和孕酮的分泌情况。向细胞中添加LH（5 - 50纳克/毫升）会导致雄烯二酮（升高2.5至3倍；P < 0.01）和孕酮（约升高1.6倍；P < 0.001）的产生呈剂量依赖性刺激。添加雌二醇 - 17β（0.3 - 300纳克/毫升）也会使雄烯二酮的分泌增加（高达5倍；P < 0.001），而在同时存在LH（20纳克/毫升）和雌二醇（300纳克/毫升）的情况下，雄激素水平比对照值高出多达12倍（P < 0.001）。相比之下，雌二醇处理可使基础（P < 0.001）和LH刺激（P < 0.001）的孕酮分泌抑制高达50%。将细胞暴露于纯化的牛抑制素（5 - 125纳克/毫升）中，雄烯二酮分泌持续比基础水平升高多达42%（P < 0.001）。抑制素还增强了LH刺激（约35%；P < 0.001）和雌二醇刺激（约20%；P < 0.05）的雄烯二酮分泌。与之形成直接对比的是，用人重组激活素 - A（1 - 50纳克/毫升）处理卵泡膜细胞会抑制LH刺激（约50%；P < 0.001）和雌二醇刺激（约30%；P < 0.005）的雄烯二酮分泌。激活素还逆转了抑制素对基础（P < 0.01）、LH刺激（P < 0.001）和雌二醇刺激（P < 0.001）的雄烯二酮分泌的正向作用，尽管单独的激活素并不影响基础类固醇输出。同时添加人重组卵泡抑素可逆转激活素对LH和雌二醇诱导的雄烯二酮分泌的抑制作用，但不改变抑制素的作用。单独的卵泡抑素既不改变基础也不改变LH刺激的雄烯二酮输出。抑制素、激活素或卵泡抑素对基础或LH刺激的孕酮分泌均无持续影响。除了证实LH和雌二醇对牛卵泡膜细胞雄激素产生的刺激作用外，这些观察结果表明颗粒细胞衍生的抑制素和激活素在调节牛卵巢卵泡膜细胞对促性腺激素和类固醇的反应中具有相反的卵泡内旁分泌作用。（摘要截选至400字）
