Fig. 8.

Lack of effect of the NO synthase inhibitor N-monomethyl-l-arginine (l-NMMA) on PDGF-induced PKG suppression and PTP1B upregulation. Cells were cultured in serum-free medium for 24 h followed by treatment for 30 min without or with 0.5 mM l-NMMA and by treatment for 24 h without or with 20 ng/ml PDGF in the continued absence or presence of l-NMMA. A: Western blots from a representative experiment. B and C: summary of results (means ± SE) from 3 experiments for PKG (B) or PTP1B (C) protein levels, normalized to α-actin. *P < 0.05 compared with control.