H. Takizawa et al., ACTIVATED IMMUNOCOMPETENT CELLS IN RAT COLITIS MUCOSA INDUCED BY DEXTRAN SULFATE SODIUM AND NOT COMPLETE BUT PARTIAL SUPPRESSION OF COLITISBY FK506, Digestion, 56(3), 1995, pp. 259-264
Administration of dextran sulfate sodium (DSS) solutions to rats induc
ed colitis which resembled mucosal lesions of human ulcerative colitis
. Recent reports have shown that some cytokines are related to the pat
hogenesis of ulcerative colitis. In the present report, we describe th
e production of two cytokines in colitis mucosa in this DSS model. Usi
ng a cytotoxicity assay and a radioimmunoassay, we observed significan
t increases in levels of tumor necrosis factor-alpha (TNF-alpha) in th
e colitis mucosa and detected interleukin-1 alpha in the mucosa of 3 o
f 5 DSS rats and an increase in TNF-alpha had a tendency to be inhibit
ed by treatment with FK506. Immunohistochemical investigation of DSS m
ucosa showed that the number of activated T cells increased at the ear
lier phase of inflammation. Luminol-dependent chemiluminescence values
and myeloperoxidase activities were increased in the late phase of co
litis and were suppressed by the FK506 treatment. These findings may s
upport the role of TNF-alpha and T-cell activation in the pathogenesis
of DSS colitis.