Growth factor action on ovarian function in polycystic ovary syndrome

Insulin-like growth factors, their receptors, binding proteins, and binding protein proteases are important in normal and abnormal ovarian follicle de velopment. IGFs stimulate ovarian cellular mitosis and steroidogenesis and inhibit apoptosis. Patterns of expression of IGF family members are charact erisitic of whether follicles are estrogen- or androgen-dominant. The PCOS follicle is androgen-dominant but does not appear to be atretic and has cha racteristic IGF family expression. Available data strongly support an intra ovarian, as opposed to endocrine, role for this growth factor family in ova rian follicle growth, steroidogenesis, and atresia.