Indoxyl sulphate (Table 3): Parallel to inducing vascular calcification, indoxyl sulphate administration to human VSMC [30,51,52,53,54] or rats with hypertension [57] or 5/6 nephrectomy [51] increased the expression of CBFA1/RUNX2, ALP, BMP2 and osteopontin, while a reduction in α-SMA, SM22-α and/or SMTN expression could be observed. This evidence concerns the gene SPP1 and Hypertension.