REPRODUCTION: PHOTIC-NEUROENDOCRINE CONTROL OF PROLACTIN

目标是阐明和理解基本的机制。 催乳素(PRL)的长期光-神经内分泌控制 季节性繁殖雄性叙利亚仓鼠(Mesocrictus)细胞功能的研究 Auratus)。研究的目的也是为了更好地理解 松果体在中枢神经系统中的作用 光周期--催乳素细胞活动的神经内分泌控制。初步研究 将决定短光周期对催乳素合成、储存、 性腺退化早期的降解和分泌。 PRL合成的变化将通过测量掺入 ~3H-亮氨酸在体外合成的催乳素 体内PRL信使RNA水平的测定。PRL存储将是 通过测量免疫活性RIA-PRL的总量来确定 培养瓶内装有来自各治疗组的脑垂体腺。PRL 体内释放将通过测量免疫反应量进行评估 各处理组仓鼠血清中的RIA-PRL。这个 PRL的降解将通过脉冲追逐标记技术进行评估。 其他研究将确定短光周期对植物生长的影响 仓鼠茎中催乳素调节因子(S)的释放 体外成纤维细胞(SME)。这些影响将与这些影响相关联 短光周期对PRL细胞活性的影响，特别是在早期 性腺退行性变的阶段。实验还将致力于 确定催乳素细胞对一种 PRL-监管暴露。将进行平行研究，其中包括 PRL细胞对已知的下丘脑PRL调节的敏感性改变 因子(多巴胺、γ氨基丁酸、促甲状腺激素释放 激素)将被测量以响应短光周期。在所有的 建议的研究松果体在调节短时反应中的作用 光周期诱导的PRL细胞功能的变化将由以下因素决定 包括去松果体的仓鼠。对长期的理解 在该物种中对催乳素的抑制控制可能会导致新的 长期抑制异常高催乳素水平的途径 下丘脑-垂体疾病和生殖功能改变的患者 功能。

The goal is to elucidate and understand the fundamental mechanisms underlying the long term photic-neuroendocrine control of prolactin (PRL) cell function in the seasonally-breeding male Syrian hamster (Mesocricetus auratus). The research is also aimed at achieving a better understanding of the pineal gland's role in the mediation of the photoperiodic-neuroendocrine control of PRL cell activity. Initial studies will determine the effects of short photoperiod on PRL synthesis, storage, degradation and secretion during the early stages of gonadal regression. Changes in PRL synthesis will be assessed by measuring the incorporation of 3H-leucine into newly synthesized PRL in vitro as well as by the measurement of in vivo levels of PRL messenger RNA. PRL storage will be determined by measuring the total amount of immunoreactive RIA-PRL in the incubation vials containing pituitaries from each treatment group. PRL release in vivo will be assessed by measuring the amount of immunoreactive RIA-PRL in the serum of hamsters from each treatment group. The degradation of PRL will be assessed via pulse-chase labelling techniques. Other studies will determine the effects of short photoperiod on the release of a PRL-regulatory factor(s) from the hamster stalk median eminence (SME) in vitro. These effects will be correlated with the effects of short photoperiod on PRL cell activity, particularly during the early stages of gonadal regression. Experiments will also be devoted to the determination of whether alterations in PRL cell sensitivity to a PRL-regulatory exposure. Parallel studies will be conducted in which changed in PRL cell sensitivity to known hypothalamic PRL-regulatory factors (dopamine, Gamma amino butyric acid, thyrotrophin-releasing hormone) will be measured in response to short photoperiod. In all of the proposed studies the role of the pineal gland in mediating short photoperiod-induced changes in PRL cell function will be determined by including pinealectomized hamsters. An understanding of the long term inhibitory control of PRL in this species could potentially lead to new approaches to the long term suppression of abnormally high PRL levels in patients with hypothalamic-pituitary disorders and altered reproductive function.