Endocrine Relationships Preceding Precocious Puberty (pilot)

基因型、营养水平、代谢信号、肥胖和生长速度都对生长发育有着深远的影响。 哺乳动物中调节下丘脑-垂体-性腺轴（HPGA）的神经内分泌系统。这些 这些因素可以改变性成熟的速度和第一次排卵（青春期）的年龄。它还没有被完全理解 这些因素中的哪一个对生殖发育具有主要影响。中枢性性早熟 青春期（CPP）是自19世纪后半叶以来一直被临床研究的现象， 涉及儿童期促性腺激素释放激素（GnRH）分泌的过早重新出现， 激活一系列垂体-性腺和身体成熟。CPP的临床状况包括 乳房初潮、月经初潮以及线性生长和骨成熟的加速。种族差异存在于 48%的非洲裔美国人，25%的西班牙裔和15%的白色女孩表现出性成熟 第二性征8岁。乳房发育开始于2 - 6岁的女孩通常 具有与CPP一致的快速进行性青春期发育。真正的CPP令人担忧，因为 可能导致性发育过早的潜在疾病。戏剧性的社会心理 CPP的影响是令人不安的，因为没有自然的发展到青少年时期。当前 CPP患者的临床治疗是给予长效GnRH激动剂。的长期目标 这项研究计划旨在阐明生殖和生长之间的发育关系， 发育中的女性，并确定影响CPP发生的特定内分泌信号。的 该试验项目的具体目的是研究牛动物模型中的长期GnRH给药 与早熟引起的青春期，以促进对机制的理解， 雌性哺乳动物青春期的开始。拟议的研究旨在建立生殖，生长， 和内分泌的特征。通过渗透泵长期给予GnRH， 将抑制HPGA（通过降低促性腺激素和性腺类固醇分泌）的动物模型， 被诱导表现出性早熟和肥胖增加。结果将提供代谢，生长， 和内分泌的关系，存在于女性与CPP，并作为未来的研究项目的基础 进一步了解生殖发育，促进CPP的替代临床治疗。

Genotype, level of nutrition, metabolic signals, adiposity, and growth rate all have profound influence on the neuroendocrine system that regulates hypothalamic-pituitary-gonadal axis (HPGA) in mammals. These factors can modify the rate of sexual maturation and age at first ovulation (puberty). It is not fully understood which of these factors has a predominant influence on reproductive development. Central precocious puberty (CPP) is a phenomonen that has been clinically studied since the latter half of the 19th century and involves the premature reemergence of gonadotropin-releasing hormone (GnRH) secretion during childhood, activating a cascade of pituitary-gonadal and physical maturation. Clinical conditions of CPP involve thelarche, menarche, and acceleration of linear growth and bone maturation. Racial differences exist in sexual maturation with 48% of African-American, ¿ 25% of Hispanic, and 15% of white girls exhibiting secondary sexual characteristics by age 8. Girls whose thelarche begins between 2 and 6 yr of age often have rapidly progressive pubertal development consistent with CPP. True CPP is of concern because of underlying disorders that may be causing premature sexual development. The dramatic psychosocial implications of CPP are troubling, as there is no natural progression into the teenage years. The current clinical treatment for patients with CPP is administration of long acting GnRH agonists. The long-term aim of this research program is to elucidate developmental relationships between reproduction and growth in developing females and identify specific endocrine signals that influence the occurrence of CPP. The specific aim of this pilot project is to investigate chronic GnRH administration in a bovine animal model with precociously induced puberty to contribute to the understanding of mechanisms underlying the onset of puberty in female mammals. Proposed research is designed to establish reproductive, growth, and endocrine characteristic of these precocious females. Chronic GnRH administration, by osmotic pump, will suppress the HPGA (via lower gonadotropin and gonadal steroid secretion) in an animal model that has been induced to exhibit precocious puberty and enhanced adiposity. Results will provide metabolic, growth, and endocrine relationships that exist in females with CPP, and serve as a basis for future research projects to further our understanding of reproductive development and facilitate alternative clinical therapies for CPP.