|Lents, Clay - UNIV OF GA|
Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 7, 2007
Publication Date: July 26, 2007
Citation: Lents, C.A., Barb, C.R. 2007. The Stimulatory Actions of Kisspeptin on Gonadotropin Secretion in Prepubertal Swine [abstract]. Society for the Study of Reproduction Annual Meeting. p. 105. Technical Abstract: To determine the effects of kisspeptin on gonadotropin secretion in prepubertal gilts were surgically fitted with a lateral intracerebralventricular (ICV) cannula using a steriotaxic procedure. Animals randomly received an ICV infusion of 150 ul sterile phosphate buffered (PBS) saline, or either 10 ug or 100 ug of ovine kisspeptin-10 (KISS) in 150 ul of PBS. Blood samples were collected every 15 min for 3 h before (period 1) and 3 h after ICV treatment (period 2) and for 105 min following an IV bolus of 100 ug of GnRH (period 3). During period 1, LH secretion was not different between treatments and averaged 0.3 ng/mL. In period 2, 10 ug and 100 ug dose KISS increased (P<0.05) LH secretion 7 and 11 fold, respectively, compared to controls. The 10 ug dose of KISS resulted in a single ovulatory like pulse of LH with rapid onset that gradually declined and returned to near basal levels by the end of period 2. The pulse of LH induced by 100 ug of KISS had a slower onset and persisted through the end of period 2, resulting in greater (P<0.01) area under the curve (AUC). All animals responded to GnRH during period 3, but AUC was greater (P<0.05) in control animals. These data illustrate that KISS can activate the hypothalamic-pituitary axis in prepubertal gilts. We postulate that increased release and(or) sensitivity to KISS is an important mechanism regulating activation of the GnRH neuronal system and initiating onset of puberty in swine.