Effects of Neurotensin and LANT-6 on Food Intake in Chicks

Abstract

Neurotensin (NT) and an NT-related peptide (Lys, Asn, NT8–13; LANT-6) are produced in the chicken brain and intestine, and these peptides are encoded by the same precursor gene (NT/LANT-6 precursor). Although it has been reported that the central administration of NT suppresses food intake in mammals, the effect of NT and LANT-6 on feeding behavior in birds has not yet been investigated. In this paper, we analyzed the expression levels of NT/LANT-6 precursor and the NT receptor (NTR1) mRNAs in the hypothalamic infundibulum, an important region for regulating feeding behaviors. We also examined the effects of NT and LANT-6 administration on food intake in chicks. Real-time PCR analysis showed that NT/LANT-6 precursor and NTR1 mRNAs had moderately high expression in the hypothalamic infundibulum. Further, in the hypothalamic infundibulum, the mRNA level of NT/LANT-6 precursor showed a trend toward increasing during postnatal development and increased 2.9-fold after a 48 hour fast, although the NTR1 mRNA level was not changed in both analyses. Contrary to our expectations, central administration of NT or LANT-6 had no effect on food intake in chicks.