Gender differences in hepatic ischemic reperfusion injury in rats are associated with endothelial cell nitric oxide synthase-derived nitric oxide

Figure 1 Serum ALT levels (n = 6, mean±SD). There were no significant differences between MS and FS groups with respect to serum ALT levels. Serum ALT levels increased significantly after hepatic I/R in M or F group vs MS or FS group (^bP<0.01 or ^dP<0.01, respectively), but they were significantly lower in F group vs M group rats (^fP<0.01). When compared with male rats pretreated with saline (M group), pretreatment of male rats with E₂ (M+E₂ group) significantly decreased serum ALT levels after hepatic I/R (^hP<0.01). Pretreatment with L-NAME in female rats or co-pretreatment with E₂ and L-NAME in male rats significantly increased serum ALT levels vs those in F or M+E₂ group rats, respectively, after hepatic I/R (^jP<0.01 or ^lP<0.01).

Figure 2 Serum TNF-α levels (n = 6, mean±SD). No significant differences existed between MS and FS groups with respect to serum TNF-α levels. Serum TNF-α levels increased significantly after hepatic I/R in M or F group vs MS or FS group (^bP<0.01 or ^dP<0.01, respectively), but they were significantly lower in F group vs M group rats (^fP<0.01). When compared with male rats pretreated with saline (M group), pretreatment of male rats with E₂ (M+E₂ group) significantly decreased serum TNF-α levels after hepatic I/R (^hP<0.01). Pretreatment with L-NAME in female rats or co-pretreatment with E₂ and L-NAME in male rats significantly increased serum TNF-α levels vs those in F or M+E₂ group animals, respectively, after hepatic I/R (^jP<0.01 or ^lP<0.01).

Figure 3 Liver tissue MDA content (n = 6, mean±SD). The differences of liver tissue MDA content between MS and FS groups were not significant. Liver tissue MDA content increased significantly after hepatic I/R in M or F group vs MS or FS group (^bP<0.01 or ^dP<0.01, respectively), but they were significantly lower in F group vs M group rats (^fP<0.01). When compared with male rats pretreated with saline (M group), pretreatment of male rats with E₂ (M+E₂ group) significantly decreased liver tissue MDA content after hepatic I/R (^hP<0.01). Pretreatment with L-NAME in female rats or co-pretreatment with E₂ and L-NAME in male rats significantly increased liver tissue MDA content vs that in F or M+E₂ group animals, respectively, after hepatic I/R (^jP<0.01 or ^lP<0.01).

Figure 4 Serum NO₂^-/NO₃^- levels (n = 6, mean±SD). Basal serum NO levels were significantly higher in FS group than those in MS group (^bP<0.01). Although serum NO levels decreased significantly after hepatic I/R in M or F group vs MS or FS group (^dP<0.01 or ^fP<0.01, respectively), they were still significantly higher in F group than those in M group rats (^hP<0.01). When compared with male rats pretreated with saline (M group), pretreatment of male rats with E₂ (M+E₂ group) significantly increased serum NO levels after hepatic I/R (^jP<0.01). Pretreatment with L-NAME in female rats or co-pretreatment with E₂ and L-NAME in male rats significantly decreased serum NO levels vs those in F or M+E₂ group rats, respectively, after hepatic I/R (^lP<0.01 or ⁿP<0.01).