Intrauterine LPS stimulates accumulation of granulocytes in the endometrium of wild type but not Tlr4^−/− mice.

<p>Mice were infused intrauterine with 100 µl of vehicle or 100 µg ultrapure LPS from <i>E. coli</i> O111:B4, the uteri collected, cross sections immunostained using a CD11b antibody for granulocytes, and the number of CD11b immuno-reactive cells counted in 4 random areas averaged over 4 independent sections from each animal. (A) Boxplot of the number of granulocytes in the endometrium 24 h after wild type (WT) or Tlr4^−/− mice were infused intrauterine with vehicle or LPS. Only the WT mice infused with LPS had more granulocytes in the endometrium than WT mice infused with vehicle; data for each treatment group were compared with WT mice infused with vehicle using the Mann-Whitney <i>U</i> test, *** P<0.001. (B) Boxplot of the number of granulocytes in the endometrium 0, 2, 4, 6, 12 or 24 h after WT mice were infused with LPS. There was increasing accumulation of granulocytes in the endometrium from 4 to 24 h; data for each time point were compared with 0 h using the Mann-Whitney <i>U</i> test, ** P<0.01, *** P<0.001. In each boxplot, the box indicates the central range between the upper and lower quartile values, the solid horizontal bar represents the median, and the whiskers indicate the 95% central range; the numbers of animals are indicated in parentheses.