What is the Origin of Intrafollicular Steroidogenesis?

This is a precise term derived from reproductive endocrinology. "Intrafollicular" means within the follicle, which is the fluid-filled sac containing the egg. "Steroidogenesis" is a compound word from "steroid" and the Greek genesis (origin or creation), describing the process of steroid hormone synthesis.

What is the Mechanism of Intrafollicular Steroidogenesis?

The mechanism follows the two-cell, two-gonadotropin theory. LH stimulates the theca cells to synthesize androgens, primarily androstenedione, from cholesterol via a series of enzymatic steps, including the action of $17alpha$-hydroxylase. These androgens then diffuse across the basement membrane into the granulosa cells. FSH stimulates the granulosa cells to express aromatase, the enzyme that converts the androgens into estrogens, predominantly estradiol. This localized, coordinated synthesis is crucial for the paracrine signaling required for a healthy ovulatory cycle.

Intrafollicular Steroidogenesis ∞ Area

Intrafollicular Steroidogenesis

Meaning

Intrafollicular steroidogenesis is the complex biochemical process occurring within the ovarian follicle, specifically involving the theca and granulosa cells, that results in the de novo synthesis of steroid hormones, primarily estrogens and androgens. This highly regulated pathway is essential for follicular development, oocyte maturation, and the establishment of the necessary hormonal environment for ovulation. The process is critically dependent on the coordinated action of gonadotropins, Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH), and specific enzyme systems. Dysfunction in this pathway is a common etiology for various reproductive endocrine disorders.