TESTICULAR CONTROL OF LH AND FSH SECRETION

睾丸对 LH 和 FSH 分泌的控制

• 批准号: 2197378
• 负责人: TONY M PLANT
• 金额: $ 18.41万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-08-01 至 1998-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2197378
• 关键词: Leydig cells; Macaca mulatta; bioassay; blood chemistry; catheterization; complementary DNA; follicle stimulating hormone; gel filtration chromatography; gonadotropin releasing factor; high performance liquid chromatography; hormone regulation /control mechanism; human genetic material tag; hypothalamic pituitary axis; inhibin; luteinizing hormone; messenger RNA; neuroendocrine system; northern blottings; radioimmunoassay; secretion; testis; testosterone

The long term objective of this proposal is to elucidate the neuroendocrine mechanisms that regulate testicular function in the rhesus monkey, a representative primate. Many of the control systems that govern reproductive processes in mammals, including the neuroendocrine axis regulating testicular function, exhibit species differences, and it is therefore to be anticipated that studies of reproductive physiology in the monkey may have direct relevance to our understanding of the control of human fertility and to the treatment of reproductive diseases in men. The focus of the present proposal is to examine the dynamic operation of the FSH-inhibin feedback loop and to evaluate the significance of this servo- system in regulating testicular function. Five Specific Aims will be addressed: l) To begin to examine the molecular biology of the negative feedback action of testicular inhibin on FSH secretion in the monkey; 2) To investigate the dynamics of inhibin induced suppression of FSH secretion; 3) To fully characterize the circulating forms of inhibin in the male rhesus monkey and to determine whether testicular secretion of an alpha-inhibin precursor peptide is a hallmark of exaggerated FSH stimulation; 4) To determine the relative role of LH and FSH in maintaining inhibin secretion by the testes; 5) To examine the notion that FSH plays an important regulatory role in governing testosterone secretion by the monkey testis. The experimental model to be employed is the juvenile male rhesus monkey, in which an adult pattern of endocrine activity in the pituitary-testicular axis is imposed by an invariant intermittent iv infusion of GnRH. For this purpose, prepubertal animals will be implanted with indwelling venous catheters, fitted with nylon jackets, and maintained in remote sampling cages that permit continuous access to the venous circulation without tranquilization and without restraint. Using this so called hypophysiotropic clamp preparation, the pituitary-testicular axis will be perturbed, using surgical interventions, passive immunoneutralization, and recombinant hormonal probes. Secretion of the pituitary gonadotropins and testicular hormones (inhibin and testosterone) will be routinely monitored using RIA. Circulating forms of immunoactive inhibin will be characterized using gel filtration and HPLC. Steady state mRNA levels for the pituitary gonadotropin subunits (LHbeta, FSHbeta and alpha), and the pituitary inhibin subunits (alpha, betaA and betaB) will be assessed by Northern blotting with monkey and human cDNA probes, respectively. Additionally, bioassays for LH, FSH and inhibin are available as needed. Surgical procedures will be conducted using standard aseptic technique with appropriate anesthesia and postsurgical analgesics.

该提案的长期目标是阐明 调节恒河猴睾丸功能的神经内分泌机制 猴子，灵长类动物的代表。许多控制系统 哺乳动物的生殖过程，包括神经内分泌轴 调节睾丸功能，表现出物种差异， 因此，可以预见的是，生殖生理学的研究 猴子可能与我们对控制的理解有直接关系 人类生育能力和男性生殖疾病的治疗。这 本提案的重点是审查 FSH-抑制素反馈环路并评估该伺服的重要性 调节睾丸功能的系统。五个具体目标 解决： l) 开始检查阴性的分子生物学 猴睾丸抑制素对FSH分泌的反馈作用2） 研究抑制素诱导的 FSH 抑制的动态 分泌; 3) 全面表征抑制素在体内的循环形式 雄性恒河猴并确定睾丸是否分泌 α-抑制素前体肽是 FSH 过高的标志 刺激； 4) 确定 LH 和 FSH 在 维持睾丸的抑制素分泌； 5）检验以下概念： FSH 在控制睾酮分泌中发挥重要的调节作用 由猴睾丸产生。所采用的实验模型是 幼年雄性恒河猴，其中内分泌的成年模式 垂体-睾丸轴的活动是由一个不变的因素强加的 间歇性静脉输注 GnRH。为此，青春期前的动物 将植入装有尼龙的留置静脉导管 夹克，并保存在远程采样笼中，允许连续 无需镇静剂即可进入静脉循环 克制。使用这种所谓的促生理钳夹制剂， 通过手术干预，垂体-睾丸轴将受到干扰， 被动免疫中和和重组激素探针。分泌 垂体促性腺激素和睾丸激素（抑制素和 睾酮）将使用 RIA 进行常规监测。流通形式 将使用凝胶过滤和 HPLC 来表征免疫活性抑制素。 垂体促性腺激素亚基（LHbeta、 FSHbeta 和 alpha），以及垂体抑制素亚基（alpha、betaA 和 betaB）将通过猴子和人类 cDNA 的 Northern blotting 进行评估 探针，分别。此外，还对 LH、FSH 和抑制素进行生物测定 根据需要提供。手术程序将使用标准进行 无菌技术并采用适当的麻醉和术后镇痛剂。