Effect of the administration of exendin‐4 on eNOS expression. (a) Capillary western blot of total eNOS and phosphorylated eNOS expression in the rat retina. The red box indicates the target protein. (b and c) Fold change in the expression of total eNOS (b) and phosphorylated eNOS (c) in the rat retina (n = 7 in control group; n = 6 in Hp + PBS group; n = 9 in other groups). (d and e) Capillary western blot and fold change in the expression of GLP‐1 receptors (GLP‐1R) (d), PI3K, and Akt (e) in the rat retina. *
P < .05, significantly different from CSF group; #
P < .05significantly different from noradrenaline without exendin‐4 group. (f) NO content in human retinal microvascular endothelial cells (n = 6, 5, 5, 6, 7, 5, and 6 for group of control, OGD, OGD + Ex‐4, OGD + Ex‐4 + Ex‐9–39‐L, OGD + Ex‐4 + Ex‐9–39‐H, OGD + Ex‐4 + l‐NAME‐L, and OGD + Ex‐4 + l‐NAME‐H, respectively). One‐way ANOVA with LSD or Dunnett's T3 test were performed. C, control group; HP, high pressure injury group; EX‐4, exendin‐4; s.c., subcutaneous injection of exendin‐4; i.v., intravitreal injection of exendin‐4; od, eye drops of exendin‐4; OGD, oxygen glucose deprivation model; EX‐9–39‐L, low concentration of exendin‐9‐39 (10 nM); EX‐9–39‐H, high concentration of exendin‐9‐39 (20 nM); l‐NAME‐l, low concentration of l‐NAME (50 μM); l‐NAME‐H, high concentration of l‐NAME (100 μM)