Fig. 14.

ANG II induces fibronectin expression via the AT₂ receptor. Rabbit proximal tubule cells were treated with losartan (1 μmol/l), an AT₁ receptor antagonist, or PD123319 (10 μmol/l), an AT₂ receptor antagonist, for 60 min or the vehicle DMSO, then stimulated with ANG II (1 μmol/l) for 48 h. At the end of incubation, cell lysates were fractionated on SDS-PAGE, and fibronectin protein expression was assessed by direct immunoblotting of cell lysates (top). Actin was included as a control for loading and the specificity of change in protein expression. A representative blot from 4 independent experiments is shown. Bar graph at the bottom represents the ratio of the intensity of the fibronectin band quantified by densitometry factored by the densitometric measurements of the actin band. Values are means ± SE from 4 independent experiments. ***P < 0.001 vs. control. ^#P < 0.001 vs. ANG II- treated cells.