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Chronic mesenteric ischemia is usually a manifestation of advanced systemic atherosclerosis. Symptoms almost always reflect midgut ischemia in the distribution of the SMA. An antegrade bypass from the supraceliac aorta can be performed with acceptable operative morbidity and is currently the preferred reconstructive technique. Surgical revascularization affords long-term symptom-free survival in a majority of patients with chronic mesenteric ischemia.

Increased mouse aortic wall expression of MCP-1 and RANTES occurs early in development of elastase-induced AAA and before onset of the chronic inflammatory response. Moreover, elastase directly stimulates AoSMC chemokine production in vitro. Elastase-induced medial SMC production of CC chemokines may therefore provide an important link between enzymatic injury, leukocyte recruitment, and aneurysmal degeneration of the aortic wall.

Ionizing radiation causes histological changes in normal tissues that resemble those resulting from the inflammatory response. Inflammation is a multistep process requiring expression of adhesion molecules on the surface of endothelial cells which results in leukocyte extravasation. E-selectin is an adhesion molecule that mediates leukocyte "rolling" on the endothelium and is required for the inflammatory response. We quantified E-selectin expression and selectin-dependent adhesion of leukocytes to human endothelial cells after X irradiation to determine whether E-selectin participates in the radiation-mediated inflammation-like response. Immunofluorescence staining of irradiated endothelial cells demonstrated expression of E-selectin on the cell surface similar to that elicited by treatment with interleukin-1 (IL-1). Radiation-mediated expression of E-selectin was dependent on dose and time and occurred at doses as low as 0.5 Gy. Furthermore, the increased adhesion of leukocytes to irradiated endothelial cells was prevented by an E-selectin-blocking antibody. Sialyl Lewis X is one of the molecules on the surface of leukocytes that adheres to E-selectin. The anti-inflammatory agents glycyrrhizin and carminic acid, which are structural analogues of sialyl Lewis X, attenuated adhesion of leukocytes to endothelial cells treated with X rays or IL-1. These data implicate a new class of anti-inflammatory agents in the prevention of adhesions of leukocytes to the irradiated vascular endothelium.

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