Nuclear microscopy investigations into the role of iron in atherosclerosis

Using nuclear microscopy we have investigated elemental distributions and c oncentrations in aortic arch tissue sections from three groups of rabbits: (a) rabbits on normal diet (normal group), (b) rabbits on a high-cholestero l diet (control group), and (c) rabbits on a high-cholesterol diet and depl eted in iron by weekly bleeding (test group). Rabbits in each group were sa crificed 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 f atty streaks and lesions, with a 2-fold average increase of iron concentrat ion in the artery wall of cholesterol fed rabbits compared to the normal gr oup. At 12 and 16 weeks the control group exhibited well-developed atherosc lerotic lesions with an accompanying 3-fold increase in iron. The test grou p showed a significant reduction of lesion formation compared to the contro ls, and only after 12 weeks was an increase in iron concentration in the ao rtic arch observed. These findings show that controlled blood letting results in reduced uptake of iron by the artery wall and delayed atherosclerotic lesion formation. T his correlation strongly suggests that iron has an important role in the ae tiology of atherosclerosis, (C) 1999 Elsevier Science B.V. All rights reser ved.