Luteinizing Hormone Regulates Testosterone Production, Leydig Cell Proliferation, Differentiation, and Circadian Rhythm During Spermatogenesis

Male reproductive health, particularly the regulation of spermatogenesis, is controlled by a complex combination of factors, including luteinizing hormone (LH) and its effects on Leydig cells (LCs). LH stimulates testosterone synthesis in LCs, which is critical for maintaining spermatogenesis and male fertility. This review examines the pathways through which LH regulates testosterone production, LC proliferation, differentiation, and circadian rhythm in human and non-human species. In particular, the signaling pathways of luteinizing hormone involved in testosterone production are discussed. Additionally, we explore LH's role in sperm maturation and quality, emphasizing its clinical implications in treating hypogonadotropic hypogonadism and diagnosing gonadal dysfunctions such as androgen insensitivity syndrome and precocious puberty. Furthermore, the potential of LH in assisted reproductive technologies for improving sperm quality is discussed. By highlighting key molecular mechanisms, this work provides insights into the therapeutic potential of LH in addressing male infertility and conditions of LC dysfunction.