Endocrine Abstracts

Kisspeptin is found in the ovary of different species including human and rat. We have recently described, through in vitro studies, that kisspeptin is under the control of sympathetic innervation of the ovary. Considering that ovarian activity of sympathetic nerves increases with ageing, it is possible that the ovarian kisspeptin also increases during this period. As a role of kisspeptin in folliculogenesis has been postulated, this increase in kisspeptin could participate in the changes in follicular dynamics that occur during the subfertility period. We conducted an in vivo study to determine if the ovarian sympathetic tone participates in kisspeptin expression during reproductive ageing. To achieve this, we measured kisspeptin mRNA and protein levels by qRT-PCR and western-blot at 6, 8, 10 and 12 months old rats, covering fertile (6 month), subfertile (8 and 10 months) and infertile periods (12 months). We also performed an in vivo blockade of β-adrenergic receptor with propranolol (5 mg/kg) and an ovarian surgery denervation to modulate sympathetic system at these ages. The non-treated rats showed an increase in kisspeptin expression at 10 and 12 months old (P<0,05) compared to 6 months old rats, and if we compared this kisspeptin levels with the noradrenaline content, we observed an almost perfect correlation (r=0.994). Ovarian kisspeptin peptide decreased both, after propranolol administration and with the surgical denervation (P<0.01 8 to 12 months compared with 6 months). These results suggest that intraovarian kisspeptin is regulated by sympathetic nerve via β-adrenergic receptor, participating locally in the ovary function and that ovarian kisspeptin could participate in follicular development with noradrenaline in reproductive ageing.

Disclosure: Fondecyt 1120147, Proyecto Gastos Operacionales y Beca Doctorado Nacional 21120454.