Figure 3.

Ca²⁺ sources responsible for the increase in intracellular Ca²⁺ concentration ([Ca²⁺]_I) due to 10 μM adenosine 5′-triphosphate (ATP), 100 nM endothelin-1 (ET-1) and 10 ng ml⁻¹ platelet-derived growth factor-BB (PDGF-BB) in myofibroblasts cultured on either Matrigel (a and b) or non-coated plastic dish (c and d). Myofibroblasts were stimulated with either 10 μM ATP, 100 nM ET-1, or with 10 ng ml⁻¹ PDGF-BB in a Ca²⁺-free solution containing 0.5 mM ethylene glycol bis(β-aminoethylether)-N,N,N',N',-tetraacetic acid (EGTA). The media was changed to a Ca²⁺-free solution containing 0.5 mM EGTA 30 s before addition of each agonist.