Figure 2.

Intracellular calcium does not play a role in VSMC proteoglycan synthesis. Human VSMCs were treated with ionomycin (0.01–10 nmol/L, which increases intracellular calcium, upper panels) or BAPTA-AM (1–10 μmol/L, a calcium chelator, lower panels) in the presence of TGF-β1 and ET-1 and metabolically labeled with [³⁵S]-SO₄ for 24 h. Proteoglycans were quantitated by the CPC precipitation assay (left) and assessed by SDS-PAGE (right) as described previously (Nigro et al 2002). Abbreviations: CPC, cetylpyridinium chloride; ET-1, endothelin-1; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; TGF, transforming growth factor; VSMC, vascular smooth muscle cell.