Fig. 4.

Effect of chronic occlusion and exercise training on basal and bradykinin (BK)-stimulated cellular distribution of eNOS and caveolin-1. Endothelial cells were isolated from control and collateral-dependent arteries of sedentary and exercise-trained pigs. Cells were fixed and probed for eNOS (green pixels) and caveolin-1 (red pixels) as described in Fig. 3. A–D, a–c: superimposed distributions of eNOS and caveolin-1 simultaneously acquired from endothelial cells of control and collateral-dependent arteries of sedentary and exercise-trained pigs. Cells were either untreated (a, basal) or treated with bradykinin for 1 min (b) or 5 min (c). A–D, d–f: to more clearly show the distribution of colocalized eNOS and caveolin-1, only the colocalized pixels (yellow pixels) obtained from the images corresponding to a, b, and c are displayed. E and F: quantitative distributions (%) of eNOS and caveolin-1 at the plasma membrane under basal conditions and following treatment with bradykinin for 1 and 5 min were calculated as described in materials and methods. G: the ratio of eNOS/caveolin-1 pixel intensity for each endothelial cell was determined from the percentage of eNOS and caveolin-1 distributed to the plasma membrane calculated as described in materials and methods. Graph legend in G pertains to E–G. Values represent means ± SE of 40–70 cells for each treatment group. *Significantly different from respective basal condition. †Significantly different from respective 1 min bradykinin. ‡Significantly different from respective sedentary condition.