Fig 3.

Effect of supplemental oxygen on smooth muscle cell proliferation (SMCp). A, No significant proliferation was observed on day 1 in any treatment group. On day (B) 3 and (C) 7, the arteriovenous fistula (AVF) operation markedly increased the 5-bromo-2′-deoxyuridine (BrdU) staining, suggestive of proliferation at all sites. However, it was not significantly altered with oxygen supplementation. D, On day 21, the AVF operation markedly increased BrdU staining at all sites, and this proliferation was significantly decreased by oxygen supplementation at the site of the fistula and the distal vein. On day (E) 42 and (F) 90, there was no BrdU staining, suggesting absence of proliferation. This suggests that SMCp is a self-limiting event. Data are expressed as percent units (positively stained BrdU cells/all cells). Data are expressed as mean ± standard error of the mean. P ≤ .05 was considered significant.