Figure 1.

Morphine treatment depletes immature B-cells. Mice were treated with morphine (M), morphine and naltrexone (M + N), naltrexone (N) or placebo (P) and analysed 7 days later. (A) Splenocytes were gated on B220⁺ cells and analysed for IgM and IgD expression. The percentages of B-cells in each gate are shown. (B) B220⁺IgM⁺IgD^- cells from (A) were analysed for CD21 and CD23 expression. The percentages of gated cells that were T1 (CD21^-) and MZ (CD21⁺) B-cells are shown. (C) B220⁺IgM⁺IgD^- cells (shaded histogram), B220⁺IgM⁺IgD⁺ cells (grey line), and B220⁺IgM^loIgD⁺ cells (black line) from (A) were analysed for CD23 expression. (D) The percentages of bone marrow cells that expressed CD34 are shown. (E) Bone marrow cells were analysed for B220 and IgM expression. The percentages of cells in each gate are shown. Data shown represent one mouse from each group.