Various studies had underlined the important role of bone marrow-derived endothelial progenitor cells (EPCS) in vasculogenesis and angiogenesis of ischemic tissue, but only a few studies had concentrated on the role of low doses of ionizing gamma radiation on EPCS in the prevention and therapy of atherosclerosis. Extended endothelial cell damage by cardiovascular risk factors can result in endothelial cell apoptosis with loss of the integrity of the endothelium. The consequences are an increased vascular permeability of the endothelium followed by facilitated migration of monocytes and vascular smooth muscle cell proliferation, resulting in a premature manifestation of an atherosclerotic lesion. A growing body of evidence suggests that circulating EPCS play an important role in endothelial cell regeneration.
The present study included 30 patients complaining of lower limb ischemia attributed to atherosclerosis and the presented data were statistically evaluated in relation to a control group of 30 normal healthy volunteers, age and socioeconomic matching volunteers.
The current study focuses on the role of low level ionizing radiation on increasing number of EPCS in atherosclerotic patients with lower limb ischemia. Present study demonstrated that low doses of ionizing radiation at 0.25 Gy caused a significant increase in the levels of CD34⁺, CD133⁺, KDR⁺ and CD133⁺KDR⁺ blood mononuclear endothelial progenitor cells in atherosclerotic patients and decrease apoptosis of these cells. Irradiation of blood of atherosclerotic patients appeared to be effective in minimizing lipid peroxidation as well as increasing the antioxidant activity such as superoxide dismutase and the level of nitric oxide which may be involved in multiple biological processes.
Low dose of ionizing radiation has an ameliorative effect on endothelial progenitor cells.