Figure 6.
Comparison of contractile responses to indomethacin (2.8 μM) in the isolated ductus arteriosus from wild-type (WT) vs COX-deleted mouse foetus. (a) 2.5% O2; (b) 12.5% O2. Wall tension (mN mm−1) prior to treatment, respectively, at 2.5 and 12.5% O2, was as follows: WT, 0.36±0.04 and 0.36±0.15; COX1−/−, 0.30±0.03 and 0.29±0.13; COX2−/−, 0.25±0.08 and 0.36±0.03. For each group, the number of experiments is given above each column, and no significant difference between wild-type and COX-deleted preparations is reached at either O2 tension. A significant difference in the panel (a) relative to COX1−/− is indicated with *P<0.05 (ANOVA). Note that in the case of wild-type and COX1−/− preparations, responses are slightly lower at 12.5 than 2.5% O2 (P<0.05).