Figure 4.

PI3K and L-type calcium channels regulate AngII-induced contractions of thoracic aorta. (A) Thoracic aortic rings were isolated from rats and pretreated with vehicle alone, LY294002 (10 µM), or PD98059 (10 µM) for 20 min, and then stimulated with AngII (1 µM). Contraction is expressed as a percent of KCl (60 mM)-induced maximum tension. Data are mean ± S.D. of two independent experiments (n = 2 for each experiment). ^*Significantly different from vehicle-pretreated aortic rings (P < 0.05). ^**Values were not statistically different from vehicle-pretreated aortic rings (P > 0.05). (B) The AngII (1 µM)-induced tension of thoracic aortic rings was measured after pretreatment with vehicle, EGTA (5 mM), nifedipine (20 µM), or thapsigargin (1 µM) for 20 min.