Endocrine Relationships Preceding Precocious Puberty (pilot)

基因、营养水平、代谢信号、肥胖和生长速度都对体重有深远的影响 调节哺乳动物下丘脑-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率和首次排卵(青春期)的年龄。它还没有完全被理解 这些因素中哪一个对生殖发育有主要影响。中枢性早熟 青春期(CPP)是自19世纪下半叶以来临床研究的一种现象， 涉及儿童时期促性腺激素释放激素(GnRH)分泌的过早重新出现， 慢性阻塞性肺病的临床情况包括 月经初潮，加速线性生长和骨骼成熟。种族差异存在于 48%的非裔美国人，25%的西班牙裔和15%的白人女孩表现出性成熟 8岁时的第二性征。乳房在2到6岁之间开始的女孩通常 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 可能导致早产性发育的潜在疾病。戏剧性的心理社会 CPP的影响令人担忧，因为青少年并不是自然发展的。海流 CPP的临床治疗是应用长效GnRH激动剂。的长期目标是 这项研究计划是为了阐明生殖和生长之间的发育关系 并确定影响CPP发生的特定内分泌信号。这个 通过性早熟诱导的青春期有助于理解 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、 以及这些早熟雌性所特有的内分泌。慢性应用促性腺激素释放激素，通过渗透压泵， 会抑制HPGA(通过降低促性腺激素和性腺类固醇的分泌) 被诱导表现出性早熟和肥胖症。结果将提供新陈代谢、生长、 和内分泌关系，存在于患有CPP的女性中，并作为未来研究项目的基础 以加深我们对生殖发育的了解，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.