Interaction of Estrogen and Progesterone on Kisspeptin-10-Stimulated Luteinizing Hormone and Growth Hormone in Ovariectomized Cows
Background/Aims: Growth hormone (GH) is necessary for optimal reproductive efficiency and its secretion is influenced by sex steroids. This study was designed to determine whether kisspeptin-10 (Kp10) could stimulate GH and if gonadal steroids enhance the GH response to Kp10 in cows. Methods and Results: Intravenous injection of Kp10 at 100 or 200 pmol/kg body weight with or without treatment with estradiol cypionate and/or progesterone increased luteinizing hormone (p < 0.01) plasma concentrations. Plasma concentrations of GH were increased following Kp10 in cows treated with estradiol cypionate and/or progesterone (p < 0.05) but not in cows treated with Kp10 without gonadal steroids. Conclusions: These data suggest that reproductive steroids enhance the sensitivity of the somatotropic axis to physiologically relevant doses of Kp10, and support the possibility that Kp10 is an integrator of luteinizing hormone and GH release.
Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Soren P. Rodning, Herris S. Maxwell, Barbara P. Steele, and James L. Sartin. "Interaction of Estrogen and Progesterone on Kisspeptin-10-Stimulated Luteinizing Hormone and Growth Hormone in Ovariectomized Cows" Neuroendocrinology 88.3 (2008): 212-215.