Fig. 7. Activation of ATM/Akt/CREB/eNOS signaling cascade by aphidicolin increases ACh-induced vessel relaxation in rat aortas. (A, B) Rat thoracic aortas were prepared and vessel relaxation assay was performed as described in the MATERIALS AND METHODS. Endothelium-intact aortic rings were treated with 20 µM aphidicolin or vehicle (DMSO) for 24 h and were precontracted with 1 µM phenylephrine, and then treated cumulatively with ACh (0.001-10 µM). The contractile level with phenylephrine (1 µM) immediately before treatment with ACh was considered as 100%. The tension curves indicate ACh-induced aortic relaxation in response to 20 µM aphidicolin or vehicle (DMSO) (A). The line graph represents the mean ± SD at each point (n=6) (B). (C-D4) In a separate experiment, after endothelium-intact aortic tissues were treated as described above, aortic proteins were extracted as described in the MATERIALS AND METHODS. Levels of eNOS, p-ATM-Ser
1981, p-Akt-Ser
473, or p-CREB-Ser
133 were measured using western blot analysis as described in
Fig. 1. All experiments were performed at least four times independently and blots shown are representative of at least four experiments (n=4). The bar graph depicts mean fold alterations above the controls (± SD). Statistical significance was evaluated using Student’s
t test. All differences were considered to be statistically significant at a
p value of <0.05. *
p<0.05.
