Kisspeptin‐10 stimulates the release of luteinizing hormone and testosterone in pre‐ and post‐pubertal male goats

Abstract

The aims of the present study were to clarify the effect of kisspeptin-10 (Kp10) on the secretion of luteinizing hormone (LH) and testosterone (T) in pre-pubertal and post-pubertal male ruminants. Four male goats (Shiba goats) were given an intravenous (i.v.) injection of Kp10 (5 µg/kg body weight (b.w.)), gonadotoropin-releasing hormone (GnRH, 1 µg/kg b.w.), or 2 mL of saline as a control at the ages of 3 (pre-pubertal) and 6 (post-pubertal) months. A single i.v. injection of Kp10 significantly stimulated the release of LH and T in both groups. The area under the response curve (AUC) of LH for a 60-min period after the i.v. injection of Kp10 was significantly greater in the pre-pubertal goats (P < 0.05). The AUC of T for a 120 min period post-injection did not differ between the two age groups. A single i.v. injection of GnRH also significantly stimulated the release of LH and T in both groups (P < 0.05). The secretory pattern of LH and T in response to GnRH resembled that in response to Kp10. These results show that the LH-releasing response to Kp10 is greater in pre-pubertal than post-pubertal male goats. They also show that Kp10, as well as GnRH, is able to stimulate the release of T in male goats.

The effect of kisspeptin on spermatogenesis and apoptosis in rats

“…A single dose of Kiss-54 was reported to cause ovulation in rats (30) and to significantly increase sex steroid levels in prepubertal fish (31). Gonadotropin increases were registered following a single IV or IM dose of Kiss-10 in prepubertal cats (32), sheep (33), and goats (34). It was reported that Kiss-10 given at varying doses reduces testosterone levels, a reduction that was attributed to testicular degeneration rather than a fall in LH secretion (25).…”

Identification of a Novel Kisspeptin with High Gonadotrophin Stimulatory Activity in the Dog

“…The plasma LH response to GnRH was about 3 times higher and the FSH response 1.5 times higher than the response to the same dose of KP-10. In contrast, in pre-and post-pubertal male goats there was no difference in the plasma profiles of LH and testosterone after the administration of GnRH or KP-10 [46] . FSH concentration also rose rapidly after canine KP-10 administration.…”

“…The response to exogenous KP-10 may be influenced by the phase of the oestrous cycle, the pubertal stage and the sex steroid environment [14,39,42,46] . The sensitivity of the canine pituitary to GnRH increases during the progression of anoestrus [35] and it is probable that the response to KP-10 may differ during the different phases of the cycle, since gonadal hormones exert positive or negative feedback on GnRH production and secretion.…”

Indução da ovulação e características ovarianas de marrãs pre-púberes tratadas com gonadotrofina coriônica humana ou kisspeptina

“…Nos sistemas de criação de suínos brasileiros, as fêmeas destinadas à reprodução que não conseguem expressar o estro até os 8 meses de idade são frequentemente descartadas do plantel (eNgbLoM et al, 2007;staNcic et al, 2011). Consequentemente, a administração de kisspeptina poderia acelerar a manifestação do estro e a ovulação nesses animais.…”

“…Em ovelhas pré-puberes, a administração intermitente de kisspeptina aumenta a secreção de LH para níveis comparáveis aos de fêmeas cíclicas adultas (redMoNd et al, 2011). Da mesma forma, a injeção única de kisspeptina induz uma descarga de LH em porcas e cabras pré-púberes (LeNts et al, 2008;saito et al, 2012), sendo que nas cabras essa resposta foi de maior intensidade em comparação aos animais púberes. Em função desses resultados, nossa hipótese é que a injeção de kisspeptina pode ser utilizada para induzir a ovulação de fêmeas suínas pré-púberes previamente estimuladas com eCG.…”