Figure 2 MIP‐1α expression after surgical trauma. Normal and macrophage‐depleted and inactivated rats (DI rats) (A) and op^+/‐ and op^‐/‐ mice (B) were subjected to intestinal manipulation. At different time points cDNA was generated from muscularis externa and analysed by quantitative polymerase chain reaction for MIP‐1α expression. The massive increase at 1 h after intestinal manipulation is completely abrogated in DI rats. Corresponding, op^‐/‐ mice do not show increased MIP‐1α levels compared with op^+/‐ mice 3 h after trauma. All samples are compared with untreated control (CTL) animals. Values are means and asterisks indicate significant differences between the indicated samples (n = 4–5).