Effects of hypoxia/reoxygenation and cytokines on adhesion of leukocytes to cerebral microvascular endothelial cells

AIM: To study the influence of hypoxia/reoxygenation ( WR) on the adhesion of neutrophils (Neu) and monocytes (Mon) to cultured bovine cerebral microvascular cells induced by tumor necrosis factor alpha (TNF-alpha) or interleukin 1-alpha (IL-1 alpha). METHODS: Bovine cerebral microvascular endothelial cells (CMEC) and smooth muscle cells (CMSMC) were exposed to normoxia or WR in the presence or absence of TNF-alpha (IL-1 alpha). The number of adhesions of Mon and Neu to CMEC and CMSMC was measured by flow cytometry. RESULTS: CMEC were subjected to hypoxia for 2 h followed by reoxygenation with TNF-alpha (2 mu g.L-1) for 2 h, the adhesion rate of CMEC for Mon and Neu were increased to 35.0 % +/- 0.9 % and 36.0 % +/- 0.6 % (the TNF-alpha treated group was 28.9 % +/- 1.1 % and 28.8 % +/- 1.3 %), respectively. CMSMC were treated as above, the adhesion rate of Mon and Neu was enhanced to 49.9 % +/- 0.4 % and 43.9 % +/- 1.4 % (the TNF-alpha treated group was 34.0 % +/- 1.9 % and 34.0 % +/- 1.3 %), respectively. CMEC and CMSMC were treated by IL-lcr, similar results were obtained. CONCLUSION: WR enhanced the adhesion of Mon and Neu to CMEC and CMSMC induced by TNF-alpha or IL-1 alpha.