Xenin reduces feed intake by activating the ventromedial hypothalamus and influences gastrointestinal transit rate in chicks

This study was conducted to determine the effects of xenin on appetite related processes in chicks. Chicks were centrally and peripherally administered xenin, and feed and water intake were quantified. Chicks responded with a linear dose-dependent decrease in feed intake to central xenin and had a quadratic type response to peripheral administration. Water intake was not affected by treatment. To determine if the lateral hypothalamus (LH) or ventromedial hypothalamus (VMH) was involved in this effect, chicks were both centrally and peripherally injected with xenin and an immunocytochemistry assay for c-Fos was conducted. Central and peripheral xenin caused increased activation of the VMH but had no effect on the LH. Finally, to determine if gastrointestinal transit rate was affected, chicks received central xenin and were gavaged with chicken feed slurry containing a visible marker. Chicks exhibited a quadratic dose-dependent response to transit rate after central xenin. These results suggest that xenin affects feeding and gastrointestinal motility through hypothalamic interactions in chicks. (c) 2007 Elsevier B.V. All rights reserved.