Radiation-induced intestinal inflammation

Abstract

Radiation induces an important inflammatory response in the irradiated organs, characterized by leukocyte infiltration and vascular changes that are the main limiting factor in the application of this therapeutic modality for the treatment of cancer. Recently, a considerable investigative effort has been directed at determining the molecular mechanisms by which radiation induces leukocyte recruitment, in order to create strategies to prevent intestinal inflammatory damage. In these review, we consider current available evidence on the factors governing the process of leukocyte recruitment in irradiated organs, mainly derived from experimental studies, with special attention to adhesion molecules, and their value as therapeutic targets.

Figure 1

Scheme showing the multistep model of leukocyte-endothelial cell interactions. The leukocyte and endothelial cell receptors that contribute to the different steps (rolling, firm adhesion and emigration) are also illustrated. Reprinted with permission. (review Gastroenterology 1998).

Figure 2

Image of mesenteric (A) and small bowel (B) venules was obtained by Intravital microscopic. Rolling and firm adherent leukocytes can be easily identified by transillumination (A) or fluorescent staining (B).

Figure 3

Mechanism proposed to explain leukocyte-cell adhesion and tissue damage caused by irradiation.