FIGURE 3.

Rate of [³H]uridine (A) and [³H]leucine (B) incorporation into RNA and protein in HUVECs exposed to 21% or 1% oxygen for 16 or 48 h. C, rate of [³⁵S]methionine incorporation into HO-1 and -2 protein in HUVECs exposed to 21% or 1% oxygen for 16 h. Bars represent means ± S.E. (n = 4 independent experiments); *, p < 0.05 for differences from the corresponding normoxic control values. D, quantification of the abundance of HO-2 mRNA in various polysome fractions from HUVECs exposed to 21% (white bars) or 1% oxygen (black bars) for 6 h. E, level of radiolabeled HO-2 protein after immunoprecipitation with anti-HO-2 antibodies in HUVECs pulsed with [³⁵S]methionine for 3 h and chased in EGM-2 medium under 21% or 1% oxygen for the times indicated. The result represents the average of four independent experiments. The protein level at 0 h was defined as 100%.