Toluidine blue staining of liver sections in the normothermia (NT; A-E) and hypithermia (HT; F-J) groups at sham, 6 hours, 12 hours, 1 day, and 2 days after asphyxial cardiac arrest (ACA). Few toluidine blue positive mast cells were observed in the NT/sham and HT/sham groups. Numbers of mast cells (arrows) were increased after ACA, with a peak in number 1 day post-ACA in the NT/ACA group. In the HT/ ACA group, the change in number of mast cells over time was similar to that observed in the NT/ACA group, but there were significantly fewer mast cells than in the corresponding NT/ACA group. CV: central vein. Scale bar=50 µm. (K) Mean numbers of toluidine blue positive mast cells (n=7 at each time; aP<0.05, significantly different from NT/sham group; bP<0.05, significantly different from the previous timepoint group; cP<0.05, significantly different from NT/ACA group). Bars indicate mean±standard error of the mean.