Figure 4.
FIR radiation induces tetrahydrobiopterin (BH4) synthesis in vivo. Rats were exposed with or without FIR-emitting sericite board for 7 days. (a) Lung endothelial cells were isolated from control and FIR group rats using CD31 and CD45 beads. Endothelial biopterin and BH4 levels were quantified by HPLC analysis. (b) GCH1, PTS, SPR, and DHFR protein expression in aorta tissues. β-actin is shown as a loading control. Protein levels were quantified by densitometric analysis. Data are shown as the mean ± SEM of three independent experiments. ∗P < 0.05 compared with control cells.