Identification and differential distribution of CART in the small intestine depending on the diet

Summary This study was aimed at identifying and locating cocaine‐ and amphetamine‐regulated transcript ( CART ) in the small intestine of broilers in relation to the diet. The feeding regime of the chicks was based on diets largely consisting of maize and one of four protein sources: post‐extraction soya bean meal ( SBM ) or non‐ GM seed meal – meal from traditional variety of soy seeds Glicine max ( FFS ) and meal from seeds of Lupinus angustifolius ( LA ) and Lupinus luteus L ( LY ). The presence of cocaine‐ and amphetamine‐regulated transcript immunoreactive ( CART ‐ IR ) in the wall of the small intestine of the chicks was determined on the basis of staining patterns produced by the immunohistochemical method ( IHC ). CART ‐ IR structures were found in the myenteric plexus ( MP ), submucosus plexus ( SP ), in endomucosal fibres, and fibres innervating miocytes and blood vessels in the muscularis membrane and adipocytes of the white adipose tissue ( WAT ) located on the perimeter of the serous membrane and single cells of the diffuse neuroendocrine system. Based on microscopic observation and result analysis, the lowest number of CART ‐ IR structures was identified in the group that was fed the SBM ‐based diet. This study confirms previous observations concerning CART distribution in the gastrointestinal tract ( GIT ) of animal and broadens current knowledge by inclusion of chicken in the list of CART ‐positive species. Moreover, this work provides evidence that dietary composition can be a factor that stimulates post‐prandial CART secretion in intestinal nerve structures.