What is the Origin of Leydig Cell Activity?

The term is named after Franz von Leydig, the German anatomist who first described these cells in 1850. The concept of 'activity' is a physiological measure of their secretory function, which is clinically quantifiable by measuring serum testosterone levels. Understanding this activity is central to male reproductive endocrinology and the diagnosis of hypogonadism.

What is the Mechanism of Leydig Cell Activity?

Leydig cell activity is fundamentally controlled by Luteinizing Hormone (LH), which is released from the anterior pituitary. LH binds to specific G-protein coupled receptors on the Leydig cell surface, activating the adenylate cyclase-cyclic AMP second messenger system. This cascade promotes the uptake of cholesterol and stimulates the enzymatic pathway of steroidogenesis, culminating in the conversion of cholesterol to testosterone. The resulting testosterone then exerts negative feedback on the hypothalamus and pituitary.

Leydig Cell Activity ∞ Area

Leydig Cell Activity

Meaning

Leydig cell activity refers to the primary function of the Leydig cells, which are interstitial cells located in the testes, specifically their capacity to synthesize and secrete androgens, predominantly testosterone. The level of this activity is a direct determinant of male endocrine status, influencing secondary sexual characteristics, libido, muscle mass, and bone density. It is tightly regulated by the pituitary gland within the hypothalamic-pituitary-gonadal axis.