Heme oxygenase 1(HO-1) is the only inducible form of HO family and its gene expression is up-regulated in many tissues exposed to a wide spectrum of noxious stimuli, including physical (irradiation, hyperthermia, etc.), chemical (heavy metals, carbon tetrachloride, etc.), and physiological (hypoxia, endotoxemia, etc.)insults. This evidence concerns the gene HMOX1 and serum lipopolysaccharide activity.