Prolactin receptor expression after the induction of hyperprolactinaemia. The levels of PRL receptor protein in transitional (T1, T2, and T3) and mature (FO and MZ) B cells were determined by flow cytometry (MFI). At the end of the treatment, spleen cells were marked with anti-CD19, anti-CD93, anti-IgM, anti-CD21, anti-CD23, and goat anti-PRL receptor. A) C57BL/6 mice; B) MRL mice and C) MRL/lpr mice. The asterisks denote statistical significance between populations with the p value shown.