Dr SIVARAJ SDEPT OF PHYSIOLOGY

ALL INDIA INSTITUTE OF MEDICAL SCIENCESNEW DELHI

20/03/2013

The mechanisms that trigger initiation of follicular growth are still not completely understood

Thought to involve bidirectional communication between germ and somatic cells through gap junctions

Paracrine factors : cytokines and growth factors (insulin-like growth factor [IGF], epidermal and fibroblast growth factors, and interleukin-1).

Lange endocrine physiology 2ed

FSH and insulin-like-growth factor (IGF) enhance each other's ability to stimulate follicle cell function

Access of IGF II to their receptors is regulated by IGF binding proteins and specific proteases ascribed a role in DF development

Son WY et al. 2011

Serum AMH level correlates with ovarian follicle number

AMH levels decline as the size of the follicle increases

In patients with polycystic ovary syndrome (PCOS), AMH levels are elevated,

Potential relevance in PCOS diagnosis and management

A useful clinical marker for the assessment of ovarian reserve

Broekmans FJ et al.2008

Aromatase and Estradiol

Estradiol by DF

Granulosa cell proliferation innon DF

DF= Dominant follicle

FSH in blood

Healthy blood supply

Accumulation of follicular fluid

Increased density of FSH receptors on its granulosa cells

Accumulation of atretogenic androgens,suchas DHT in the non DF

As the DF grows vascularization of the theca layer increases

More efficient delivery of cholesterol to theca cells and better exposure to circulating gonadotropins