Effect of exposing HUVECs to flow on their expression of genes for chemokines and adhesion receptors in response to TNF. (A) Stained gels showing DNA amplified by RT-PCR from mRNA extracted from HUVECs that were cultured for 26 hours under static conditions (S) or exposed to shear stress of 0.3 Pa or 2 Pa (F). TNF (100 U/mL) was added for the last 2 hours. Actin is shown as a loading control unmodified by treatment. Gels are from individual experiments, which were carried out on 3 occasions. (B) Densitometry of DNA bands obtained by RT-PCR for HUVECs treated with 100 U/mL TNF and cultured under static conditions or exposed to shear stress of 0.3 Pa or 2.0 Pa. Data are mean ± SEM from 3 experiments under each condition. ANOVA showed significant effect of culture conditions on expression of IL-8, GRO-α, and E-selectin (*P < .05, **P < .01).