Follicular oestrogen synthesis: the 'two-cell, two-gonadotrophin' model revisited.
Level 5 - mechanism / opinion, no new human data
Narrative mechanistic review with no original clinical trial or human quantitative data
PubMed 8056158 · doi:10.1016/0303-7207(94)90278-x
What was done
This review examined updates to the classical 'two-cell, two-gonadotrophin' endocrine model of follicular oestrogen synthesis, focusing on cellular receptor distribution, steroidogenic enzyme expression (such as CYP17), and local paracrine signalling between granulosa and thecal cells.
What was found
The abstract reports no numerical data. It summarizes mechanistic findings showing that CYP17 (17-hydroxylase/C17-20-lyase) is expressed exclusively in thecal cells under LH regulation, while FSH receptors are expressed exclusively in granulosa cells. Granulosa cells express androgen receptors to respond to theca-derived androgens, and during preovulatory recruitment, acquire LH receptors linked to aromatase activity and inhibin production. Granulosa-derived inhibin acts in a paracrine feedback loop to enhance LH-stimulated thecal androgen synthesis, amplifying overall oestrogen synthesis.
Why it matters
It updates the foundational model of ovarian physiology by defining the specific molecular and paracrine feedback loops—particularly involving inhibin and androgen receptors—that govern preovulatory follicle selection and estrogen production.
Limits
The abstract provides a qualitative conceptual review without systematic search methods, clinical trials, or quantitative measurements.
Cited by
- supports In women, theca cells produce testosterone in the gonads, functioning analogously to Leydig cells in men.