Does iron inhibit calcification during atherosclerosis?

• Published in: Free radical biology & medicine Vol. 53; no. 9; pp. 1675 - 1679
• Main Authors: Rajendran, Reshmi, Minqin, Ren, Ronald, John A., Rutt, Brian K., Halliwell, Barry, Watt, Frank
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2012
• Subjects: Animals; Aorta - pathology; arteries; Atherosclerosis; Atherosclerosis - etiology; Atherosclerosis - metabolism; Atherosclerosis - pathology; calcification; Calcium; Calcium - metabolism; Calcium - physiology; Diet, High-Fat - adverse effects; etiology; Free radicals; Iron; Iron - metabolism; Iron - physiology; Male; microscopy; Organ Specificity; oxidative stress; PIXE; Plaque, Atherosclerotic - etiology; Plaque, Atherosclerotic - metabolism; Plaque, Atherosclerotic - pathology; Rabbits; RBS; Spectrometry, X-Ray Emission; spectroscopy; STIM; Vascular Calcification - etiology; Vascular Calcification - metabolism; Vascular Calcification - pathology; X-radiation; RBS; PIXE; STIM; Free radicals; Calcium; Atherosclerosis; Iron
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2012.07.014

Oxidative stress has been implicated in the etiology of atherosclerosis and even held responsible for plaque calcification. Transition metals such as iron aggravate oxidative stress. To understand the relation between calcium and iron in atherosclerotic lesions, a sensitive technique is required that is quantitatively accurate and avoids isolation of plaques or staining/fixing tissue, because these processes introduce contaminants and redistribute elements within the tissue. In this study, the three ion-beam techniques of scanning transmission ion microscopy, Rutherford backscattering spectrometry, and particle-induced X-ray emission have been combined in conjunction with a high-energy (MeV) proton microprobe to map the spatial distribution of the elements and quantify them simultaneously in atherosclerotic rabbit arteries. The results show that iron and calcium within the atherosclerotic lesions exhibit a highly significant spatial inverse correlation. It may be that iron accelerates the progression of atherosclerotic lesion development, but suppresses calcification. Alternatively, calcification could be a defense mechanism against atherosclerotic progression by excluding iron. ► Calcium and iron show a negative correlation in advanced atherosclerotic lesions in rabbits. ► This spatial anti-correlation is highly localized. ► The average lesion iron concentration was 63.5ppm. ► The average lesion calcium concentration was 1882ppm.