Objective: 

Neuropeptide Y (NPY) and peptid YY (PYY) are important neuromediators related to feeding behaviour in mammals. New peptide hormone kisspeptin has an essential role for the onset of puberty and gonadal function by stimulating the secretion of gonadotropin-releasing hormone. There are very limited studies regarding effect of kisspeptin on blood NPY and PYY concentrations. We have therefore investigated effects of kisspeptin on plasma levels of NPY and PYY in relation with feeding behaviour.

Methods: 

Young male Sprague-Dawley (7 weeks old) rats were used in this study. Kisspeptin (20nmol/kg/day) was intraperitoneally administered for 12 days (n=8). Control animals received vehicle alone (n=8). Animals were decapitated one hour later after the last kisspeptin administration on the 12th day of experiments and blood samples were collected. Plasma concentrations of NPY and PYY were analysed by ELISA. Mann-Whitney U Test was used for statistical evaluations.

Results: 

Kisspeptin treatment increased plasma NPY level (P<0.01). Plasma PYY concentration was decreased in kisspeptin treated group compared to control (p<0.05).

Conclusions: 

Results from this study demonstrate for the first time that exogenous kisspeptin administration decrease plasma PYY level. The present findings indicate that kisspeptin may have an orexigenic effect in the post-pubertal young male rat by increasing NPY and decreasing PYY levels.