Transcription activity of genes encoding three gonadotropin subunits: (α, LHβ, FSHβ) de- pends on specific cis- and trans-acting regulatory elements located on their promoters. Gonadotropin releasing hormone (GnRH) is a crucial neurohormon stimulating these genes transcriptional activity. Pulsatile intracerebroventricular microinjections of GnRH, β-endorphin, vasoactive intestinal peptide (VIP) and galanin in ovariectomized rats revealed their significant role in the modulation of gonadotropin subunits gene expression.

GnRH (GnRH) is a key regulator of the expression of specific genes encoding three gonadotropin subunits (?, LH? And FSHb) in the pituitary. The promoter of the gene protein LHb SF-​​1, EGR-1 and SP-1 to form a complex, three-part regulatory element responsible for full activation of transcription of the gene by GnRH. The position -443 promoter sequence identified CCATTTTTGG (called CArG box) responsible for gene activation by pulsed LHb released GnRH. Dependent upon the specific GnRH-subunit gene expression is associated with activation while two protein binding sites on the promoter ETS.