Indices of atheromatous plaque stability are enhanced after 9 months exposure to 100 kBq/l ¹³⁷Cs.

<p>A: αSMA immunostaining for smooth muscle cells (αSMA^<b>+</b> cells: green; nuclei: blue, n = 5 sections per animal) and B: αSMA quantification within the plaques. No difference is observed after 6 months exposure, however, after 9 months exposure, a significant increase in αSMA^<b>+</b> area is noted for the group exposed to 20 kBq/l. C: Picrosirius red staining for collagen was performed on aortic sinus cryosections. Representative images obtained at magnification x100. n = 5 sections per animal. D: Quantification of collagen in the plaque. After 6 and 9 months of exposure to 100 kBq/l ^<b>137</b>Cs, collagen content was increased in lesions. E: This result was paralleled by an increase in col3 mRNA expression, assessed by RT-qPCR, in the whole aorta. Results are expressed as mean ± SEM of n = 5–8. *p<0.05 vs Cs 0 control group.