Interaction of Estrogen and Progesterone on Kisspeptin-10-Stimulated Luteinizing Hormone and Growth Hormone in Ovariectomized Cows

Abstract

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.

Characteristics of the Stimulatory Effect of Kisspeptin-10 on the Secretion of Luteinizing Hormone, Follicle-Stimulating Hormone and Growth Hormone in Prepubertal Male and Female Cattle

“…Kisspeptin neurons are found in the hypothalamus [7][8][9], and kisspeptins strongly stimulate the secretion of gonadotropin through a G protein-coupled receptor known as GPR54 [3][4][5]. The actions of these peptides are thought to involve mainly stimulating GnRH's neuronal activity through GPR54 [3][4][5].An administration of kisspeptin, either centrally or peripherally, has been shown to elicit the release of gonadotropins in ruminants [10][11][12][13][14][15] as well as in rats [16,17], pigs [18], monkeys [19] and humans [20,21]. However, in cattle, only two in vivo studies have been conducted [13,14], and the precise effects of kisspeptin on the secretion of pituitary hormones under physiological conditions are unknown.…”

“…However, in cattle, only two in vivo studies have been conducted [13,14], and the precise effects of kisspeptin on the secretion of pituitary hormones under physiological conditions are unknown.…”

“…An administration of kisspeptin, either centrally or peripherally, has been shown to elicit the release of gonadotropins in ruminants [10][11][12][13][14][15] as well as in rats [16,17], pigs [18], monkeys [19] and humans [20,21]. However, in cattle, only two in vivo studies have been conducted [13,14], and the precise effects of kisspeptin on the secretion of pituitary hormones under physiological conditions are unknown.…”

Does Kisspeptin signaling offer a new way to treat infertility?

“…Until recently, the only known humoral action of Kisspeptin was on the HPG axis. However, evidence from cows [19,38,39] and rats [24] is emerging of a stimulatory action on pituitary growthhormone release. In addition to the pituitary, hypothalamus and placenta, GPR54 is expressed in other regions of the brain, as well as the spleen, liver, pancreas and gonads [1,2].…”

1086 Effect of investigational kisspeptin/metastin analog, TAK-683, on luteinizing hormone secretion at different stages of the luteal phase in goats

“…63: [221][222][223][224][225][226] 2017) K isspeptin is mainly produced in the hypothalamus and is biologically active at various lengths of 10 to 54 amino acids. Kisspeptin-54 or kisspeptin-10, either the full length or the C-terminal amidated 10-amino-acid sequence of kisspeptin, potently stimulates luteinizing hormone (LH) secretion in both male and female mammals [1][2][3][4][5][6][7]. Our previous study showed that the stimulatory action of kisspeptin-10 on LH secretion is attributable to the stimulation of gonadotropin-releasing hormone (GnRH) neurosecretion into the hypophyseal portal circulation in castrated goats [8].…”