The action of LH-releasing hormone and five analogues on oestradiol, oxytocin and vasopressin secretion by bovine granulosa cells in culture

Abstract

ABSTRACT The release of oxytocin, arginine-8-vasopressin and oestradiol-17β by bovine granulosa cells in culture was analysed either with or without LH-releasing hormone (LHRH), its agonists (cyclo [Pro1dPhe6] LHRH and des 1–3, 10[dAla6] LHRH) or antagonists ([dPhe2dPhe6] LHRH, [dPhe2dPhe(NH2)6] LHRH or cyclo [Pro1dPhe2dPhe6] LHRH). All preparations used stimulated granulosa oxytocin and oestradiol secretion. Vasopressin release was significantly increased after all treatments with LHRH antagonists, but not after LHRH or its agonists. Our observations demonstrated a direct influence of LHRH and its analogues on the secretion of oestrogen and nonapeptide hormones by bovine granulosa cells. A comparison of the effects of LHRH, its agonists and antagonists suggests that the action of these peptides at the hypophysial and ovarian level is relatively independent. Journal of Endocrinology (1993) 136, 491–496