l-Lys ameliorates vascular calcification in adenine-induced uremic rats. (A) Calcification of the thoracic aorta is visualized by von Kossa staining. Representative micrographs from group LP (a), group Ade (b), group Gly (c), and group Lys (d) are shown. Group LP has no calcification, whereas groups Ade and Gly show extensive medial calcifications (black area). Group Lys has no von Kossa–positive area. (B) Macroscopically, alizarin red staining shows no vascular calcification in group LP. The majority of group Ade (six of eight animals) and all rats in group Gly have extensive calcification (red area) throughout the vasculature. In group Ade, the calcification of the thoracic aorta is relatively weak in two of eight animals. The majority (six of eight animals) of group Lys has no calcification. Only two of eight animals in group Lys develop partial vascular calcification. (C) In contrast with arteries from group LP, those from groups Ade and Gly contain high levels of calcium, magnesium, and phosphate. Compared with group Ade, arteries from group Lys have significantly low amounts of these minerals. All results are presented as means±SD (n=6–8 in each group). ***P<0.001 (Dunnett’s test). Scale bar, 100 μm.