Role of mucosal mast cells in visceral hypersensitivity in a rat model of irritable bowel syndrome

Abolishment of TNBS-induced visceral hypersensitivity in mast cell deficient rats

“…Coelho et al reported that mast cell degranulation induced by lipopolysaccharide and BrX-537A resulted in a significant increase in the rectal sensitivity to mechanical distention in rats, and that the hypersensitivity was significantly suppressed by pretreatment with doxantrazole, an inhibitor of mast cell mediator release (Coelho et al, 2000). More recently, it was demonstrated that visceral hypersensitivity occurred in the rat acetic acid colitis model in association with the higher degranulation rate of colonic mucosal mast cells (La et al, 2004). These findings point to the key role played by intestinal mast cells in development of visceral hypersensitivity in rats.…”

Role of nociceptin/orphanin FQ receptors in the decrease of mucosal mast cells caused by acute stress in the rat colon

“…The differences may be due to the special fixing and staining techniques needed to identify MMCs by light microscopy. In fact the number of MMCs in the rat distal colonic mucosa was 81 ± 18/mm 2 (Santos et al, 2001) and 62 ± 3/mm 2 (La et al, 2004) in toluidine blue-stained sections after Carnoy's fixation, approximately 100/mm 2 in toluidine blue-stained sections after paraformaldehyde fixation (Ohashi et al, 2007), and 2.6 ± 0.3/crypt unit in paraformaldehyde-fixed sections stained with the specific RMCPII antibody (Traver et al, 2010). However in two different studies by the same group, in which MMCs were counted in low-pH Alcian blue-safranin stained sections after Carnoy's fixation of distal colon mucosa and submucosa, their number was reported to be approximately 20/mm 2 (Bradesi et al, 2002) as well as 85±8/mm 2 (Barreau et al, 2004), suggesting that discrepancies in MMC number are not only attributable to differences in fixing/staining techniques.…”

Functional somatic syndrome: how it could be relevant to rheumatologists

“…55 In addition to tryptase, an increase of histamine release in IBS has been also reported. 56 Further, using a rat model of IBS, La et al 57 reported that pretreatment of a mast cell stabilizer doxantrazole reduced not only the degradation rate of mucosal mast cells but also visceral hypersensitivity to rectal distention. Zuo et al 58 showed that stabilization of mast cells with sodium cromoglycate reduced cellular recruitment to the injured nerve and suppressed the development of hyperalgesia, proposing the importance of mast cells and their mediators in neuropathic pain.…”