Cocaine- and amphetamine-regulated transcript peptide (CART) in the nerve fibers of the porcine gallbladder wall under physiological conditions and after Salmonella Enteritidis lipopolysaccharides administration.

Cocaine- and amphetamine-regulated transcript (CART) peptide is the substance distributed in various parts of the nervous system. The majority of previous studies described this substance in the brain, where it takes part in regulatory processes connected with the food intake. CART is also present in the peripheral nervous system, especially in the enteric neurons and nerves located in the wall of the stomach and intestine, but many aspects of distribution and functions of this peptide in the digestive organs remain unknown. The aim of the present study was to investigate the changes of CART-positive nerves in the porcine gallbladder after administration of Salmonella Enteritidis lipopolysaccharides (LPS) using the single immunofluorescence technique. In control animals the average number of CART-positive nerves per observation field (0.1mm²) amounted to 5.38±0.32, 11.11±1.56 and 2.97±0.24 in gallbladder neck, body and fundus, respectively. LPS administration caused the increase in the number of CART-positive fibers in all parts of gallbladder, and these values amounted to 12.74±0.51, 19.75±0.19 and 5,1±0,05 in the gallbladder neck, body and fundus respectively. The obtained results suggest that CART is involved in the neuronal regulatory processes in the porcine gallbladder under physiological conditions, but also during pathological processes, but exact functions of this peptide in this organ remain unexplained and require the further investigation.