What is the Origin of Luteinizing Hormone Signal?

The term "luteinizing" is derived from the Latin luteus, meaning yellow, referring to the hormone's role in stimulating the formation of the corpus luteum (yellow body) in the ovary. The LH signal was identified as part of the complex endocrine feedback system controlling reproduction and sexual development. Its pulsatile release pattern is a key element of its physiological effectiveness.

What is the Mechanism of Luteinizing Hormone Signal?

The hypothalamus releases Gonadotropin-Releasing Hormone (GnRH) in a pulsatile manner, which stimulates the pituitary to release LH. LH travels through the circulation and binds to specific G protein-coupled receptors (GPCRs) on the surface of gonadal cells. This receptor activation initiates an intracellular signaling cascade, primarily involving the cAMP pathway, which ultimately drives the expression of steroidogenic enzymes necessary for the synthesis of sex hormones like testosterone and progesterone.

Luteinizing Hormone Signal

Meaning

The crucial endocrine message transmitted by Luteinizing Hormone (LH), a glycoprotein hormone secreted by the anterior pituitary gland, which acts as a primary regulator of gonadal function in both sexes. In males, the LH signal stimulates the Leydig cells in the testes to synthesize and secrete testosterone. In females, it triggers ovulation and corpus luteum formation, which then produces progesterone. This signal is integral to the Hypothalamic-Pituitary-Gonadal (HPG) axis.