Biosynthesis of gonadotropins in vivo

Abstract

GnRH is potent stimulator of gonadotropin's alpha and beta chains synthesis in vivo. Stimulation of LHbeta gene transcription requires pulsatile GnRH administration but the transcription of alpha subunit can be stimulated independently of GnRH mode of administration. Castration increases whereas in vivo estradiol and testosterone replacement decreases the rate of gene transcription of pituitary gonadotropin subunits. Thyroid hormones can enhance or diminish the pituitary levels of LHbeta and FSHbeta subunit mRNAs in female rats. Inhibin, activin and follistatin were shown to be potent regulators of FSHbeta gene expression.