Regulation of follicle-stimulating hormone β and common α-subunit messenger ribonucleic acid by gonadotropin-releasing hormone and estrogen in the sheep pituitary

Abstract

The effect of gonadotropin-releasing hormone (GnRH) and/or estradiol (E2) on pituitary messenger ribonucleic acid (mRNA) levels of luteinizing hormone β (LHP), follicle-stimulating hormone β (FSHP) and the common α-subunit were determined in anterior pituitary glands from ovariectomized (OVX) ewes. Hypothalamo-pituitary disconnected (HPD) ewes receiving appropriate hormonal treatment were used to assess the relative roles of GnRH and E2 in directly regulating FSHβ and α-subunit mRNA levels. Levels of LHβ mRNA were increased in OVX animals compared with intact controls, and E2 treatment of OVX animals significantly reduced mRNA levels of LHβ and FSHβ. HPD substantially reduced FSHβ and α-subu..