Reconstitution of CCL2-induced hyperalgesia by adoptive transfer of macrophages derived from Wistar, but not from Dark Agouti (DA) rats.

<p>(<b>A</b>) Mechanical nociceptive thresholds were quantified after i.pl. injection of 3 µg CCL2 with prior leukocyte depletion by systemic injection of CTX (filled triangles), 3 µg CCL2 with prior systemic injection of solvent (cyclo-phosphamid (CTX) treatment (open circles), or solvent of CCL2 without CTX treatment (filled circles). CTX injections were performed 3 d with 10 mg/kg and 1d 50 mg/kg before cell and/or CCL2 treatment. (<b>B</b>) Representative dot blots (x-axis: forward scatter (FSC) – cell size; y-axis: sideward scatter (SSC) – cell granularity) for leukocyte subpopulations in peripheral blood of untreated (left) and CTX-treated Wistar rats (right) are shown by flow cytometry. Gates were set on beads (for quantification), neutrophils, lymphocytes and monocytes. (<b>C–F</b>) Wistar and DA rats were leukocyte-depleted by i.p. injection with CTX followed by i.pl. injection of different numbers of macrophages from either Wistar or DA rats, 30 min later, by i.pl. injection of 3 µg CCL2. Injection of 2×10⁶ macrophages without concomitant injection of CCL2 served as a negative control. (<b>C</b>) Wistar rats reconstituted with cells from Wistar rats. I.p. injections of solvent only served as a negative control for CTX treatment (open triangles) with the same injection pattern. (<b>D</b>) Wistar rats reconstituted with cells from DA rats. (<b>E</b>) DA rats reconstituted with cells from Wistar rats. (<b>F</b>) DA rats reconstituted with cells from DA rats. (*p<0.05 compared to time point 0 h, Two Way RM ANOVA, Student-Newman-Keuls, n = 6). Data are presented as means ± SEM.