Phenylephrine dose-response curves for isolated thoracic aorta from wild-type (WT) and Slc29a1-null (KO) mice after exposure to hypoxia.

Tissues were incubated for 30 min at 37˚C in KPSS buffer at resting tensions of 500 mg after which they were depolarized with 100 mM KCl. Tissues were then incubated for 60 min under either normoxic or hypoxic conditions, and then exposed to increasing concentrations of phenylephrine (Panels A and B). Panels C (WT) and D (KO) show the effect of 1 μM NBMPR on the response to hypoxia. NBMPR was administered 15 min prior to hypoxia, and then removed prior to the construction of the phenylephrine dose-response relationship. Each point is the mean ± SEM from 6 (Panel A & B) or 5 (Panel C and D) experiments. *Significant difference between treatment groups (Student’s t-test for unpaired samples, *P<0.05).