Luteinizing hormone and human chorionic gonadotropin: distinguishing unique physiologic roles

Abstract

Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) are integral components of the hypothalamic–pituitary–gonadal axis, which controls sexual maturation and functionality. In the absence of signaling through their shared receptor, fetal sexual differentiation and post-natal development cannot proceed normally. Although they share a high degree of homology, the physiologic roles of these hormones are unique, governed by differences in expression pattern, biopotency and regulation. Whereas LH is a key regulator of gonadal steroidogenesis and ovulation, hCG is predominantly active in pregnancy and fetal development. Emerging evidence has revealed endogenous functions not previously ascribed to hCG, including participation in ovulation and fertilization, implantation, placentation and other activities in support of successful pregnancy. Spontaneous and induced mutations in LH, hCG and their mutual receptor have contributed substantially to our understanding of reproductive development and function. The lack of naturally occurring, functionally significant mutations in the β-subunit of hCG reinforce its putative role in establishment of pregnancy. Rescue of reproductive abnormalities resulting from aberrant gonadotropin signaling is possible in certain clinical contexts, depending on the nature of the underlying defect. By understanding the physiologic roles of LH and hCG in normal and pathologic states, we may better harness their diagnostic, prognostic and therapeutic potential.

Chinese abstract

促黄体激素（LH）和人绒毛膜促性腺素(hCG)是下丘脑－垂体－性腺轴整体的组分，控制性成熟和性功能。它们共享受体信号的缺乏，胎儿性分化和出生后发育不能正常进行。尽管它们共享高度的同源性，但这些激素的生理作用是独特的，表达方式、生物效能和调节是不同的，然而，LH 是性腺甾体合成和排卵的关键调节剂，hCG的主要作用是妊娠及孕胎儿发育。新的证据显示以前没有归于HCG的内源性的功能，包括参与排卵和受精，种植，胎盘形成和其他支持妊娠成功的活动。LH，hCG和它们共同的受体自发和诱发突变提供了我们对生殖发展与功能的理解。hCG β-亚单位天然缺乏，功能上明显突变加强了它确定妊娠的公认作用。依据潜在缺陷的本性，因异常促性腺激素信号导致的生殖异常的复苏在某些临床环境下是可能的。通过对LH和hCG 正常和病理状态生理作用的理解，我们可以较好地利用它们的诊断，预测和治疗潜能。

• Function
• hCG
• infertility
• LH
• LHCGR
• mutation
• ovulation
• polymorphism