ELEMENTAL CHANGES IN ATHEROSCLEROTIC LESIONS USING NUCLEAR MICROSCOPY

The roles of iron and other trace metals in the aetiology of heart and brain diseases has been a subject of keen research because of the abi lity of metal ions to participate in reactions involving free radicals , which have been implicated in many of these diseases. Unstained free ze dried tissue sections from the aorta of New Zealand white rabbits f ed with a 1% cholesterol diet for 12 weeks were scanned with a 2 MeV p roton beam using the National University of Singapore nuclear microsco pe facility. Results from 6 test and 4 control rabbits show that there is an average of seven-fold increase in iron and an average of nearly two-fold increase in phosphorus in the atherosclerotic lesion compare d with healthy tissue. The increase in iron adds weight to the hypothe sis that iron-catalyzed free radical reactions may be associated with the development of atherosclerosis. A depletion of other elements anal yzed was seen in the lesion. Elemental mapping also showed the occurre nce of granules rich in sodium, chlorine and potassium at the interfac e between lesioned and non-lesioned tissue.