Authors: E Bresciani N Pitsikas L Tamiazzo M Luoni I Bulgarelli D Cocchi V Locatelli A Torsello
Publish Date: 2014/03/22
Volume: 31, Issue: 7, Pages: 647-652
Abstract
Ghrelin a 28aminoacid peptide isolated from the stomach is the natural ligand of the GHsecretagogues receptor1a GHSR1a and so far the only discovered circulating appetitestimulating hormone Similarly to ghrelin many synthetic compounds belonging to the GHS family stimulate both GH secretion and feeding whereas some stimulate GH secretion only In the past years studies have focused on the potential of the GHS to stimulate GH release during longterm treatment in humans and experimental animals Few data are available about the extraendocrine effects of the GHS during several weeks of treatment particularly in old rats The aim of the present study was first to identify the lowest dose of hexarelin giving maximal stimulation of food intake both in young 3monthold and old rats 24monthold A doseresponse study 80–320 µg/kg sc revealed that hexarelin at the dose of 80 µg/kg gave reproducibly maximal stimulation of food consumption in young as well as in old rats Second we evaluated the effect of 8week daily sc treatment with hexarelin in young and old male rats The outcome of the chronic study was that hexarelin 80 µg/kg sc once daily maintained a persistent significant orexigenic action throughout the treatment period both in young and old rats Interestingly hexarelin treatment did not affect body weight gain either in young or old rats We conclude that hexarelin is endowed with longlasting orexigenic activity and might represent a potential therapeutic approach for pathological conditions characterized by a decline in food intake
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