Fig. 4.

ANG II induces collagen-I synthesis and cell proliferation via activation of calpain in PMCs. PMCs were incubated with ANG II (10⁻⁷ M) in the presence or absence of the calpain inhibitor MDL28170 (20 μM) for 24 h, after which calpain activity was detected as described in Methods, intracellular collagen-I protein levels were measured by Western blots, and cell proliferation was detected by BrdU kit. A: relative calpain activity in PMCs (n = 3). B: representative immunoblots of collagen-I. C: changes in relative density of collagen-I protein to GAPDH according to B (n = 3). D: changes in cell proliferation of PMCs (n = 8). Data are expressed as mean ± SE. *P < 0.05 vs. control, #P < 0.05 vs. ANG II.