FIGURE 1.

The Cyp2c44 epoxygenase mediates the basal and AA-stimulated proliferative and tubulogenic activities of endothelial cells. Primary cultures of lung endothelial cells from wild-type (WT) and Cyp2c44^−/− (KO) mice in serum-free media (SF) or in serum-free media containing arachidonic acid (AA) (5 μm) or 11,12-EET (EET) (1 μm) were: A, cultured 48 h prior to the addition of [³H]thymidine (0.1 μCi/well) and then their proliferation quantified as described under “Experimental Procedures.” Values are averages ± S.D. calculated from three experiments, each performed in quadruplicates. * and ** indicate significant differences (p < 0.05) between untreated or treated WT and KO cells, respectively; B and C, plated onto Matrigel and the formation of tube-like structures analyzed by light microscopy. B, representative images of capillary like structures taken 6 h after plating. C, capillary network formation was quantified as described under “Experimental Procedures,” and the values are averages ± S.D. of branch number per microscope field, calculated from three experiments each performed in triplicates. * and ** are as in A.