The effect of oxyhemoglobin on the proliferation and migration of cultured vascular smooth muscle cells

Vascular smooth muscle cells (VSMC) proliferation and migration have previously been regarded as central features in vascular disease. However, the potential roles of vascular cell proliferation and migration in cerebral vasospasm following subarachnoid hemorrhage (SAH) have not been extensively studied. Since oxyhemoglobin (oxyHb) is implicated in the pathogenesis of cerebral vasospasm, 1-200 μM of oxyHb was used in this study to mimic the clinical situation, and the effects of oxyHb on the proliferation and migration of cultured rat aortic smooth muscle cells were investigated. The morphological and biochemical techniques used included the methyl thiazolyl tetrazolium (MTT) assay, flow cytometry cell cycle analysis, monolayer-wounding assay, and Boyden's chamber migration assay. Results show that low concentration of oxyHb (1 μM, 10 μM) would increase the proliferation and migration of VSMC, but on the contrary, high concentration of oxyHb (100 μM, 200 μM) would inhibit the proliferation and migration of VSMC. The proliferative ability of VSMC turned out to be a bidirectional alteration under the influence of oxyHb. It was consistent with the clinical course. Therefore, anti-VSMC proliferation and migration may be useful in the therapy of cerebral vasospasm after SAH. © 2008 Springer-Verlag.