INTESTINAL CYTOKINES IN INFLAMMATORY BOWEL-DISEASE AND INVASIVE DIARRHEA

In the intestine large numbers of bacteria and their products are sepa rated by a single epithelial layer from resident inflammatory cells (m acrophages and lymphocytes). Many of these bacterial products, such as lipopolysaccharides and peptidoglycans, are potent stimulators of fre e radical and inflammatory cytokine production by macrophages. This ca n occur in vivo in response to mucosal invasion by enteropathogenic ba cteria or because of inappropriate activation of these cells, as in ch ronic inflammatory bowel disease. In this review we present evidence f or production of cytokines in normal intestine and in intestinal infla mmatory conditions. The adverse effects of cytokine production upon in testinal homeostasis, in particular disruption of epithelial integrity and prothrombotic changes in the vascular endothelium, are also discu ssed.