Chemokine mRNA and protein in the liver over 0–48 hours after a single injection of ricin (40 μg/kg) in C57BL/6 mice. A,C,E. Messenger RNA for CXCL1/KC, CXCL2/MIP-2, and CCL2/MCP-1(JE) is shown as a ratio of specific message/value of a house-keeping gene (18S or L32), determined by Northern blotting (CXCL1/KC) or by ribonuclease protection assay (CXCL2/MIP-2, CCL2/MCP-1). Specific mRNA for these chemokines was not detected at 0 hours. Two mice were analyzed per time point. B,D,E. Chemokine protein in liver homogenates after ricin challenge, quantified by paired antibody enzyme-linked immuno-absorbent assay, described in Materials and Methods. Shown is the mean +/− 1 SD. Homogenates were analyzed in duplicate from each of two mice per time point (14 mice total per cytokine). *, p< 0.05, comparing values at the indicted hours with that at 0 hours.