Effect of H2S on the serum levels of liver enzymes and ammonia in mice. The serum levels of (A) ALT, (B) AST, and (C) ammonia were measured on the last day of the experiment. Values are presented as the mean ± SEM. n=6-9. *P<0.05 vs. control; **P<0.01 vs. control; #P<0.05 vs. TAA; ##P<0.01 vs. TAA. ALT, alanine transaminase; AST, aspartate transaminase; TAA, thioacetamide; NaHS, sodium hydrogen sulfide.