Edema and cyclooxygenase-2 protein expression in the brain irradiated with heavy-ion beams

Abstract

Formation of cerebral edema is acute response of brain tissue to a large radiation and may contribute to delayed pathology (vascular collapse and tissue necrosis) that often lead to permanent loss of function. Therefore, it is very important to reduce formation of cerebral edema for protect potential damage of normal brain tissue. Cyclooxygenase-2 (COX-2) is the inducible form of the 2 prostaglandin-synthesizing enzymes and is believed to be an important mediator of cell injury in inflammation. However, it is unclear what the role of COX2 activity in the brain irradiated with heavy-ion beams. In the present study, the left cerebral hemispheres of adult rats were irradiated at dose 50 Gy with heavy-ion beams, expression of COX2 protein and the effect of treatment with a COX2 inhibitor on cerebral edema were determined and compared at 2-24 hrs after irradiation. The results indicated that radiation-induced cerebral edema was dependent on COX2 activity.