Fig. 8.

EPA impairs arachidonic acid metabolism stronger than DHA. (A) Enzyme-dependent oxygenation products of arachidonic acid converted by COX-2 (PGE2 and TXB2), 12-LO [12(S)-HETE] and 5-LO (LTB4) determined in PBMC supernatants. Gray bars, PBMC were alloreactively activated; open bars, unstimulated PBMC. Means ± SEM of n = 4. (B) COX-2 expression in stimulated monocytes. PBMC from buffy coats were incubated without or with 100 µM EPA or DHA for 20 h and subsequently activated for another 4 h with LPS. Monocytes were identified by staining for CD14. Expression of COX-2 was flow-cytometrically analyzed by intracellular staining. Upper graph: Data are expressed as means ± SEM of n = 5, t: P = 0.102 versus ctrl. Right scales denote mean fluorescence intensity (MFI) depicted as dots. Lower graph: Representative histograms of LPS-activated monocytes stained for CD14 and COX-2. Marker was set in reference to the unstimulated control.