Figure 4

Dynamic compression inhibits IL-1β induced iNOS expression and production of nitrite release. Effects of 15% dynamic compressive strain on (a,b,c) iNOS expression and (d) nitrite production in unstrained and strained constructs cultured under no treatment conditions or with 10 ng/ml IL-1β and/or 10 μmol/l SB203580 for 6, 12 and 48 hours. The ratio of the relative expression level of iNOS was calibrated to the mean value for the unstrained (untreated) control and normalized to GAPDH. Ratios were expressed on a logarithmic scale (arbitrary units). Bars represent the mean and standard error of the mean of 16 to 18 replicates from four separate experiments. Two-way analysis of variance with post hoc Bonferroni-corrected t-tests was used to compare data: **P < 0.01 and ***P < 0.001. GAPDH, glyceraldehyde 3-phosphate dehydrogenase; iNOS, inducible isoforms of the nitric oxide synthase.