FIGURE 6.

Chronic morphine redistributes c-Src from membrane rafts to detergent soluble non-raft membranes. HEK/HA-DOR cells kept for 1 h either in the absence (cn) or presence of 100 nm etorphine (eto) or 1 μm morphine (mor) were homogenized in the presence of 1% (v/v) Triton X-100, before low density membrane rafts (L) and high density non-raft membranes (H) were separated by sucrose density gradient ultracentrifugation. Equal fraction volumes were subjected to Western blot analysis using antibodies recognizing the HA-DOR, EGF receptor (EGFR), c-Src, and H-Ras. The quality of membrane fractions was verified by staining the blots with the membrane raft and non-raft markers caveolin and transferrin receptor (TfR), respectively. Note the disappearance of c-Src from the low density, detergent-insoluble fraction after chronic morphine treatment. Representative blots of three different experiments are shown.