Different effects of immobilization stress on the mRNA expression of antioxidant enzymes in rat peripheral organs

To understand the role of antioxidant enzymatic defenses in reactive oxygen species (ROS) injury following immobilization stress, we examined the effect on mRNA expression of four antioxidant enzymes, manganese superoxide dismutase (Mn-SOD), copper and zinc containing SOD (Cu/Zn-SOD), glutathione peroxidase (GPx) and catalase (CAT), in peripheral rat organs. Immediately after 6 h of immobilization, the mRNA levels of all antioxidants examined were markedly decreased in the liver, while 24 h after the cessation of immobilization, the mRNA expressions recovered to baseline levels. In contrast, the adrenal mRNA levels of Mn-SOD and CAT were increased by stress, and the increased levels of these mRNAs were maintained 24 h after cessation of stress. The stress did not affect the mRNA levels of antioxidants in the heart, lung and kidney. Our results suggest that the antioxidant defense status in peripheral tissues is influenced by immobilization stress and that tissue-specific regulation mechanisms of antioxidant enzymes exist in rats.