NEURAL INFLUENCE ON HYPOPHYSEAL-GONADAL FUNCTION

神经对垂体-性腺功能的影响

• 批准号: 2197332
• 负责人: HAROLD G SPIES
• 金额: $ 27.65万
• 依托单位: OREGON REGIONAL PRIMATE RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-09-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2197332
• 关键词: Macaca mulatta; RNase protection assay; brain stem; desipramine; estradiol; estrogen receptors; excitatory aminoacid; gonadotropin releasing factor; high performance liquid chromatography; hormone regulation /control mechanism; hypothalamus; immunocytochemistry; in situ hybridization; luteinizing hormone; messenger RNA; microdialysis; neurons; neuropeptide Y; norepinephrine; ovariectomy; prazosin; radioimmunoassay; receptor expression; secretion; tyrosine 3 monooxygenase

Infertility often results from disruption of menstrual cyclicity and/or ovulation: processes known to be driven by specific hypothalamic signals. By monitoring neurosecretions in either naturally ovulating or ovariectomized (OVX) rhesus macaques, we observed a 10-fold increase in gonadotropin-releasing hormone (GnRH) secretion during an estradiol- 17beta (E2)-induced luteinizing hormone (LH) surge. No less than 14 neurotransmitter/neuropeptide(s) are implicated in the regulation of GnRH secretion. Because adrenergic receptors are found on GnRH neurons, we initially focus on norepinephrine (NE) and neuropeptide Y (NPY), which are colocalized in noradrenergic cells and stimulate GnRH gene expression and secretion in E2-conditioned animals, including macaques. Aim 1a will resolve if the preovulatory rise in ovarian E2 stimulates NE and NPY secretion in conjunction with the E2-induced GnRH/LH surge. Aim 1b will decipher if blockade of either NE or NPY receptor activity by selective antagonists blocks the GnRH/LH surge. Continuous push-pull perfusion or microdialysis will be performed in the mediobasal hypothalamus (MBH) of both intact and OVX monkeys with or without treatment of prazosin (NE antagonist) and (Ac[3-(2,6 dichlorobenzyl)tyr(27,36)D-Thr(32)]NPY-(27- 36)amide (NPY antagonist). Changes in perfusate levels of NE, NPY and GnRH will be analyzed by high-performance liquid chromatography and radioimmunoassays, respectively. Aim 2 addresses the morphometric and intracellular evidence of how E2 influences NPY/NE/GnRH secretion. Aim 2a will determine if estrogen receptors are localized in NE and/or NPY neurons, if NPY is produced in NE neurons, and if NE/NPY terminals synapse with hypothalamic GnRH neurons. Histological sections of the MBH and brainstem (i.e., locus coeruleus/lateral tegmentum) will be examined for the localization of neurons that express estrogen receptor mRNAs (by in situ hybridization) and NE (i.e., dopamine-beta-hydroxylase), NPY and GnRH (by immunocytochemistry). Aim 2b will quantitate E2-induced changes in NPY and NE (i.e., tyrosine hydroxylase) mRNA contents in identified loci of brainstem and hypothalamus by ribonuclease protection assay. Aims 3 and 4 examine how synaptic NE secretion interacts with other putative neuromodulators to regulate GnRH release. Aim 3a will determine if blockade of NE transporter activity (presynaptic NE reuptake) by the antidepressant, desipramine, acutely stimulates NE, hence GnRH, release. Aim 3b will show that continuous desipramine infusion suppresses NE/GnRH secretion, and establish if GnRH pulses can be reinitiated by pulses of NE or neuroexcitatory amino acids (i.e., N-methyl-D,L-aspartate). Microdialysis cannulae implanted in the MBH of OVX monkeys will be used for acute (3a) or continuous (3b) desipramine treatment, pulsatile NE or N-methyl-D,L-aspartate infusion (3b) and microdialysate collection for NE and GnRH measurements (3a,b). Aim 4a will examine by in situ hybridization whether chronic intrahypothalamic desipramine can suppress retrogradely NE transporter, tyrosine hydroxylase, or NPY mRNAs in brainstem NE cells. Aim 4b will search for evidence of E2 downregulation of NE transporter message in NE neurons. These studies will indicate the importance of specific neurochemical on GnRH secretion thereby increasing the knowledge of biological and pathological events in fertile and neurally depressed, infertile female primates.

不孕症通常是由于月经周期中断和/或 排卵：已知由特定下丘脑驱动的过程 信号. 通过监测自然排卵期或排卵期的神经分泌物， 在卵巢切除（OVX）的恒河猴中，我们观察到 促性腺激素释放激素（GnRH）分泌在雌二醇- 17 β（E2）诱导的促黄体生成激素（LH）激增。 不少于14 神经递质/神经肽参与GnRH的调节 分泌物 因为肾上腺素能受体存在于GnRH神经元上， 最初集中于去甲肾上腺素（NE）和神经肽Y（NPY）， 共定位于去甲肾上腺素能细胞并刺激GnRH基因表达 和分泌E2条件动物，包括猕猴。 目标1a将 如果排卵前卵巢E2的升高刺激NE和NPY， 分泌与E2诱导的GnRH/LH激增有关。 目标1b将 通过选择性地阻断NE或NPY受体活性， 拮抗剂阻断GnRH/LH峰。 连续推拉灌注或 微透析将在下丘脑内侧基底（MBH）进行， 用或不用哌唑嗪（NE）治疗的完整和OVX猴 拮抗剂）和（Ac[3-（2，6-二氯苄基）tyr（27，36）D-Thr（32）]NPY-（27- 36)酰胺（NPY拮抗剂）。 灌流液中NE、NPY和 将通过高效液相色谱法分析GnRH， 放射免疫测定。 目标2涉及形态测量和 E2如何影响NPY/NE/GnRH分泌的细胞内证据。 目的 2a将确定雌激素受体是否位于NE和/或NPY中 如果NE神经元中产生NPY，并且如果NE/NPY终末 与下丘脑GnRH神经元形成突触。 MBH的组织切片 和脑干（即，蓝斑/外侧被盖）进行检查 对于表达雌激素受体mRNA的神经元的定位（通过 原位杂交）和NE（即，多巴胺-β-羟化酶）、NPY和 GnRH（免疫细胞化学法）。 目标2b将定量E2诱导的变化 在NPY和NE中（即，酪氨酸羟化酶）mRNA含量 用核糖核酸酶保护试验检测脑干和下丘脑的基因位点。 目的3和4研究突触NE分泌如何与其他神经元相互作用。 推定的神经调节剂来调节GnRH释放。 目标3a将决定 如果NE转运蛋白活性（突触前NE再摄取）被阻断， 抗抑郁药地昔帕明急性刺激NE，从而刺激GnRH释放。 目的3b将显示持续地昔帕明输注抑制NE/GnRH 分泌，并建立GnRH脉冲是否可以通过脉冲重新启动， NE或神经兴奋性氨基酸（即，N-甲基-D，L-天冬氨酸）。 将使用植入OVX猴MBH的微透析插管 对于急性（3a）或连续（3b）地昔帕明治疗，脉动NE或 N-甲基-D，L-天冬氨酸输注（3b）和微透析液收集， NE和GnRH测量（3a，B）。 目标4a将通过现场检查 慢性下丘脑内注射地昔帕明能否抑制杂交 逆转录NE转运蛋白，酪氨酸羟化酶，或NPY mRNA， 脑干NE细胞 目标4 b将寻找E2下调的证据 NE神经元的NE转运体信息。 这些研究表明， 特定神经化学物质对GnRH分泌重要性，从而增加 生物学和病理学事件的知识， 神经抑郁不育的雌性灵长类动物