Androgen and follicle-stimulating hormone interactions in primate ovarian follicle development

We have previously shown that androgens stimulate early stages of follicula r development and that granulosal androgen receptor (AR) gene expression is positively correlated with follicular growth. The present study was aimed at elucidating potential interactions between FSH and androgens in follicul ar development. Study groups included eight normal cycling rhesus monkeys ( five follicular and three luteal-phase), eight testosterone (T)-treated, an d four FSH-treated animals. Examination of sequential ovary sections reveal ed selective colocalization of AR and FSH receptor (FSHR) messenger RNAs (m RNAs) in healthy, growing follicles. Moreover, individual follicles demonst rate a highly significant (P < 0.001) positive correlation between FSHR and AR mRNA levels in all study groups. Androgen treatment significantly incre ased granulosa cell FSHR mRNA abundance (by approximately 50-100%, dependin g on follicle size). FSH treatment increased granulosa AR mRNA levels only in primary follicles. The finding that T augments follicular FSHR expressio n suggests that androgens promote follicular growth and estrogen biosynthes is indirectly, by amplifying FSH effect, and may partially explain the enha nced responsiveness to gonadotropin stimulation noted in women with polycys tic ovary syndrome.