Transport of AEA across HUVEC membranes.

(A) Time-course of the uptake of [³H]AEA from the extracellular space (movement in) or of the release of [³H]AEA from endothelial cells preloaded with [³H]AEA (movement out), in the presence of 10 μM ATFMK (100% = 420 ± 40 or 320 ± 30 fmol/10⁶ cells, for the in-and-out transport, respectively). # designates the effect of 10 μM AM404 on the release of [³H]AEA at 20 minutes. (B) Dependence of the release of [³H]AEA on the concentration of E2, E2-BSA, epi-E2, or cortisol. (C) Representative chromatogram of the lipids extracted from the culture media of HUVECs, untreated (control), or treated with 100 nM E2 for 4 hours. The peaks coeluted with authentic AEA and their areas were within the linearity range of calibration curves (inset). Values are reported as means ± SD. In panel B, *P < .01 and **P < .05 compared with untreated control (P > .05 in all other cases).