Cocaine- and amphetamine-regulated transcript immunoreactive nerve fibres in the mucosal layer of the canine gastrointestinal tract under physiological conditions and in inflammatory bowel disease

Abstract

ABSTRACT:The objective of this study was to determine the effect of canine inflammatory bowel disease (IBD) on the density of cocaine-and amphetamine-regulated transcript (CART) immunoreactive nerve fibres in the mucosa of different sections of the gastrointestinal tract. Fibre density was analysed in mucosal specimens from the duodenum, jejunum and descending colon of healthy dogs and patients with inflammatory bowel disease of varying intensity. Nervous fibres were stained in single-cell immunofluorescence assays. The density of CARTimmunoreactive fibres was determined using a semi-quantitative approach by counting the number of fibres in the field of view (0.1 mm 2 ). An increase in the density of CART-immunoreactive fibres was observed in dogs with moderate and severe IBD in comparison with healthy subjects. The results suggest that the presence of CART in enteric nerve fibres could play a role in the pathogenesis and development of canine IBD.

Cocaine and Amphetamine Regulated Transcript (CART) Expression Changes in the Stomach Wall Affected by Experimentally Induced Gastric Ulcerations

“…The results of Q-PCR technique obtained in the present experiment demonstrated for the first time the presence of mRNA encoding CART in the stomach of healthy pigs, complementing the existing and only immunocytochemical data on its expression in the gastrointestinal tract of this species [ 11 , 12 , 31 , 34 , 40 ]. Since different mechanisms are engaged in the regulation of mRNA expression and final peptide abundance, the results of Q-PCR technique and immunohistochemistry may vary in the same tissues [ 44 ].…”

“…In healthy animals, singular, irregularly arranged submucosal CART-immunoreactive gastric perikarya were observed only in sporadic studies (present study; [12,32,39]) or were completely absent [11,31,34,40] suggesting their minor importance for intramural regulation of the stomach mucosa secretory function. The reasonable explanation for the abovementioned minor variations presented by different authors seem to result from tissue sampling differences, as described before.…”

“…Interestingly, in the other parts of gastrointestinal tract (in healthy animals), as an esophagus [ 33 ] and intestines [ 40 , 41 ], CART-immunoreactive submucosal neurons were encountered, although most of the CART-positive perikarya were also located in the myenteric plexus. Submucosal perikarya project mainly to the mucosa, other submucosal ganglia and submucosal blood vessels [ 42 ].…”

“…In the intestinal inflammatory studies, the number of CART-IF myenteric neurons was increased in ulcerative colitis in humans [ 9 ] and inflammatory bowel disease in dogs [ 40 ], while experimental colitis [ 5 ] and proliferative enteropathy [ 49 ] in pigs reduced the number of myenteric perikarya.…”

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

“…Moreover, it cannot be excluded that CART in neuronal structures of the gallbladder may act (like in the central nervous system) as an endogenous antioxidant and exhibits neuroprotective and neurotrophic effects, especially during neuronal cells injury [2,24,27,43]. It is all the more probable that relatively large number of previous studies showed the changes in the number of CART-positive enteric nervous during a wide range of intestinal and extra-intestinal processes [15,21,33], and such fluctuations were also noted during the present study.…”