MEASUREMENT OF HYPOTHALAMIC HORMONE RELEASE

总体目标是确定数量和时间关系 选择性下丘脑激素的分泌和 催乳素和促黄体生成素。 该方法将涉及同时 监测下丘脑和垂体前叶激素分泌。 具体目的是：（1）检验睾丸激素， 特别是睾酮，升高LHRH而抑制LH。 我们将尽 这是通过监测LHRH灌注液的茎正中隆起（SME） 通过推拉插管（PPC）和LH采集清醒公羊血液中的LH， （2）为了检验以下假设， 性腺类固醇对LH和LHRH分泌具有不同的时间效应。 我们将通过监测SME中LHRH浓度的变化来做到这一点 PPC收集的灌流液，以及在三个期间内完整母羊血液中的LH 发情周期的各个阶段;（3）为了检验这一假设， 光周期诱导的催乳素分泌变化主要是由 通过多巴胺（DA）分泌的变化。 我们将通过监测 DA、DA代谢物和血管活性肠肽浓度的变化 肽（VIP）在PPC灌注液的SME的清醒母羊暴露于 长和短光周期。 将在静脉血中测量催乳素; (4)为了验证吗啡能提高催乳素分泌的假设 主要是通过减少多巴胺的分泌。 我们会监测多巴胺，多巴胺代谢物， PPC灌流液中TRH和VIP浓度以及血液中催乳素浓度 清醒母羊用生理盐水或吗啡处理;（5）为了测试 哺乳通过减少DA分泌诱导催乳素释放的假说 以及升高TRH或VIP分泌。 我们会监测多巴胺，多巴胺代谢物， PPC灌流液中TRH和VIP的浓度和血液中催乳素的浓度 清醒的母羊之前，期间，和之后哺乳;和（6）为了测试 环境温度升高引起催乳素释放假说 主要由TRH分泌增加介导。 我们会监视检察官 PPC灌注液中DA代谢产物、TRH和VIP浓度和催乳素 在暴露于升高的 环境温度。

The overall aim is to define quantitative and temporal relationships between secretion of selected hypothalamic hormones and secretion of prolactin and luteinizing hormone. The approach will involve simultaneous monitoring of hypothalamic and anterior pituitary hormone secretion. Specific aims are: (1) To test the hypothesis that testicular hormones, particularly testosterone, elevate LHRH while depressing LH. We will do this by monitoring LHRH in perfusates of the stalk median eminence (SME) collected by push-pull cannulae (PPC) and LH in blood of conscious rams, wethers, and testosterone-treated wethers; (2) To test the hypothesis that gonadal steroids have divergent temporal effects on LH and LHRH secretion. We will do this by monitoring changes in LHRH concentrations in SME perfusates collected by PPC, and LH in blood of intact ewes during three stages of the estrous cycle; (3) To test the hypothesis that photoperiod-induced changes in prolactin secretion are mediated primarily by changes in secretion of dopamine (DA). We will do this by monitoring changes in concentrations of DA, DA metabolites, and vasoactive intestinal peptide (VIP) in PPC perfusates of the SME of conscious ewes exposed to long and short photoperiods. Prolactin will be measured in venous blood; (4) To test the hypothesis that morphine elevates prolactin secretion primarily by reducing DA secretion. We will monitor DA, DA metabolites, TRH, and VIP concentrations in PPC perfusates and prolactin in blood of conscious ewes treated with saline solution or morphine; (5) To test the hypothesis that suckling induces prolactin release by reducing DA secretion and elevating TRH or VIP secretion. We will monitor DA, DA metabolites, TRH and VIP concentrations in PPC perfusates and prolactin in blood of conscious ewes prior to, during, and after suckling; and (6) To test the hypothesis that prolactin release induced by elevated ambient temperature is mediated primarily by increased secretion of TRH. We will monitor DA, DA metabolites, TRH, and VIP concentrations in PPC perfusates and prolactin in blood of conscious ewes before, during, and after exposure to elevated ambient temperatures.