The effects of interleukin-6 and cytokine-induced neutrophil chemoattractant-1 on α₂-macroglobulin production in rats.

We investigated the effects of interleukin-6 (IL-6) and cytokine-induced neutrophil chemoattractant-1 (CINC-1) on α(2)-macroglobulin (α2M) production in rats. IL-6-rich and CINC-1-rich fractions were separated from serum obtained from rats 12 h after injection with turpentine oil using gel-chromatography. Sexual dimorphism was observed in the peak levels of α2M after injection of IL-6-, CINC-1-, or a mixture of IL-6-and-CINC-1-rich fractions. No significant differences in α2M levels were observed in males after injection with IL-6- or CINC-1-rich fractions and those injected with normal serum obtained from healthy rats (control). In contrast, serum levels of α2M, 6 to 120 h after injection of a mixture of IL-6- and CINC-1-rich fractions were significantly higher than in control rats. These results suggest that IL-6 and CINC-1 contribute to α2M production in rats only when IL-6 and CINC-1 act synergistically.