The effect of short fasting on the hypothalamic neuronal system of kisspeptin in peripubertal female lambs

•The effect of fasting on the expression of kisspeptin neurons in peripubertal lambs.•Fasting elicited the decrease of kisspeptin synthesis in the hypothalamic areas.•Kisspeptin may represent a link between metabolic cues and reproductive processes. Changes in the metabolic state induced by feed restrictions have a negative effect on the reproduction in mammals and result in the delayed puberty onset. Kisspeptin (kp) has been demonstrated as a pivotal regulator of GnRH/LH secretion during puberty. To elucidate the involvement of kp in the hypothalamic secretory function in altered metabolic state, the expression of kp protein was investigated in peripubertal female lambs after short fasting. The experiment was conducted on immature 32-weeks old Merino lambs fed standard diet (n=5) or fasted for 72h (n=5). The localization and expression of kp was evaluated using immunohistochemistry. Serum LH concentration was determined using radioimmunology. In the hypothalami of fasted sheep, the number of kp perikarya and the percent of density of neuronal kp network in the caudal part of the nucleus arcuatus were significantly less (P