Developmental expression of the neurotensin gene in the rat liver
This study determined whether the neurotensin gene is expressed during early development of the liver. Neurotensin (NT), a gut tridecapeptide localized mainly to the distal small bowel and brain of adults, is an important hormone regulating gut motility, secretion and mucosal growth. Expression of NT peptide and the gene is found in fibrolamellar hepatocarcinomas, a variant of hepatocellular carcinoma, but not in the normal adult liver. Northern and in situ hybridization techniques were used to determine expression of the neurotensin gene (NT/N) in the normal developing liver. NT/N is expressed in the fetal and early postnatal rat liver, but expression is repressed in the liver of the adult. In situ hybridization confirms the authors' Northern data and demonstrates a random distribution of NT/N expression in the fetal and 3-day postnatal liver. The authors conclude from this study that NT/N is expressed during early development of the rat liver with subsequent repression in the adult. NT/N may be reexpressed with malignant transformation of the liver.