Deleterious vascular effects of indoxyl sulfate and reversal by oral adsorbent AST-120

Abstract Background In chronic kidney disease (CKD), blood vessels are permanently exposed to uremic toxins such as indoxyl sulfate (IS). We hypothesized that IS could alter vascular tone and that reducing its serum concentration could be beneficial. Design We studied acute and longer-term effects of IS and AST-120, an oral charcoal adsorbent, on vascular reactivity, endothelium integrity and expression of adhesion molecules VCAM-1 and ICAM-1 in aortic rings of normal and uremic wild type (WT) mice in vitro , and the cardiovascular effects of AST-120 in both WT and apoE−/− mice with CKD in vivo . Results In vitro , 1.0 mM IS acutely reduced vascular relaxation (64% for IS 1.0 mM vs. 80% for control, p  In vitro , AST-120 restored normal vascular function and prevented IS induced endothelial cell loss and ICAM-1/VCAM-1 upregulation. In vivo , AST-120 treatment of CKD mice (1) improved vascular relaxation (72% vs. 48% maximal relaxation in treated vs. untreated mice, p  Conclusion IS appears to be an important contributor to the vascular dysfunction associated with CKD. AST-120 treatment ameliorates this dysfunction, possibly via a decrease in serum IS concentration.