Abstract: 【Abstract】Objective To investigate the relationship between the function of intestinal macrophages and the microinflammation in uremic rats. Methods Male Sprague-Dawley rats were randomly divided into sham surgery group and uremia group. Blood levels of endotoxin, hs-CRP, IL-6 and TNF-α were assayed. The ultrastructure of macrophages was examined by transmission electron microscopy. Immunochemistry of the intestinal sections was used to analyze the expression of CD11a and iNOS, the active markers of macrophages, as well as the expression of intercellular adhesion molecule-1 (ICAM-1) and TGF-β. Quantitative real-time PCR and western blot were employed to assess the mRNA and protein levels of early growth response gene 1 (EGR1) and toll-like receptor 4 (TLR4). Results The blood levels of endotoxin, IL-6, TNF-α and hs-CRP were significantly higher in uremia group than in sham surgery group (t=-5.145, -3.776, -3.553 and -10.468 respectively; P=＜0.001, 0.001, 0.002 and ＜0.001 respectively). The macrophages in uremia group showed fewer cytoplasmic protrusions and pseudopodia. The intestinal macrophages in uremia group exhibited heavier staining of CD11a, iNOS, ICAM-1 and TGF-β, and higher mRNA and protein levels of EGR1 and TLR4. Conclusions In uremia rats, intestinal macrophages differentiated towards proinflammatory phenotype,
which was related to the microinflammatory status of the rats.

Key words: Macrophage, Microinflammation, Uremia