BIOSYNTHESIS OF GONADOTROPINS IN-VIVO

GnRH is potent stimulator of gonadotropin's alpha and beta chains synt hesis in vivo. Stimulation of LH beta gene transcription requires puls atile GnRH administration but the transcription of a subunit can be st imulated independently of GnRH mode of administration. Castration incr eases whereas in vivo estradiol and testosterone replacement decreases the rate of gene transcription of pituitary gonadotropin subunits. Th yroid hormones can enhance or diminish the pituitary levels of LH beta and FSH beta subunit mRNAs in female rats. Inhibin, activin and folli statin were shown to be potent regulators of FSH beta gene expression.