Kisspeptin participation in deleterious ghrelin effects on spermatogenesis

MAESTRI G; FIOL DE CUNEO M; BIANCONI S; VINCENTI LM; CARLINI VP; PORETTI B; MARTINI AC; SCHIÖTH HB

Mar del Plata

Congreso; SAIC-SAI-SAFE 2016; 2016

Physiological mechanisms that control energy balance are reciprocally related to those that control reproductive function. In previous work we have shown that chronic intrahypothalamic ghrelin (Ghr) administration (42 days), an orexigenic peptide of 28 amino acids, decreases epididymal sperm concentration and motility in mice, these results correlate with a reduction in plasma testosterone concentration. In this study, we investigated the involvement of kisspeptin (Kiss-1) system and its receptor (GPR54) in deleterious effects on spermatogenesis after chronic Ghr central administration. Albino Swiss adult male mice were implanted with osmotic pumps (Alzet) Model 1007D (0.5 l / hour-7 days) or model 2006 (0.15 l / hour-42 days) on hypothalamus and infused with sterile cerebrospinal fluid (CSF-control) or different Ghr doses (0.3 or 3.0 nmol / ul). Animals were sacrificed and the hypothalamus dissected to assess the expression of genes encoding gonadotropin releasing hormone (GnRH), Ghr receptor (GHRS), Kiss1 and GPR54 by real time PCR. Results show a significant decrease of relative Kiss-1 expression (F = 10.25, p ≤ 0.05) and its receptor GPR54 (F = 11.34, p≤ 0.05) in animals treated per 7 days with Ghr 3,0 nmol/ul, while peptide administration for 42 days only decreases GPR54 expression (F = 9.03; p ≦ 0.05). No significant differences were found in GHRS or GnRH expression (p> 0.05). This paper provides new evidence about possible mediators involved in Ghr deleterious effect on male reproductive system, indicating that this peptide induces a negative modulation at central level on the expression of Kiss-1 and / or its receptor.