JNK inhibition decreases ANG II-induced IRS-1 Ser632, Ser307, and Ser302 phosphorylation. A: VSMCs were pretreated with SP600125 (30 nM, 30 min) followed by stimulation with ANG II (100 nM) for 5 min. Western blotting with an antiphosphospecific antibody for Ser632 IRS-1 was performed (n = 7). B: VSMCs were pretreated with SP600125 (30 nM, 30 min) followed by stimulation with ANG II (100 nM) for 30 min. Total IRS-1 was immunoprecipitated, followed by Western blotting with an antiphosphospecific antibody for Ser307 IRS-1 (n = 3). C: VSMCs pretreated with JNK inhibitor SP600125 at 30 nM for 30 min were stimulated with ANG II for 60 min, immunoprecipitated, and then immunoblotted with Ser302 phosphospecific IRS-1 antibody. Bar graphs represent means ± SE (n = 3). *P < 0.05 compared with no stimulation; #P < 0.05 compared with stimulation without JNK inhibitor.