Nuclear microscopy investigations into the role of iron in atherosclerosis

Abstract

Using nuclear microscopy we have investigated elemental distributions and concentrations in aortic arch tissue sections from three groups of rabbits: (a) rabbits on normal diet (normal group), (b) rabbits on a high-cholesterol diet (control group), and (c) rabbits on a high-cholesterol diet and depleted in iron by weekly bleeding (test group). Rabbits in each group were sacrificed at 4-week time intervals, at 4, 8, 12 and 16 weeks. As early as 4 weeks, the aortic arches of control rabbits showed signs of fatty streaks and lesions, with a 2-fold average increase of iron concentration in the artery wall of cholesterol fed rabbits compared to the normal group. At 12 and 16 weeks the control group exhibited well-developed atherosclerotic lesions with an accompanying 3-fold increase in iron. The test group showed a significant reduction of lesion formation compared to the controls, and only after 12 weeks was an increase in iron concentration in the aortic arch observed. These findings show that controlled blood letting results in reduced uptake of iron by the artery wall and delayed atherosclerotic lesion formation. This correlation strongly suggests that iron has an important role in the aetiology of atherosclerosis.