[Opioid peptides effect on lipid peroxidation in long-term stress]

It was shown in rats, that injection of opioid peptides (dynorphin A (1-13), DSLET and DAGO) decreased the stress-induced activation of lipid peroxidation in liver tissue and plasma. Dynorphin A (1-13) manifested the most expressed antioxidant effect in liver tissue. It not only decreased lipid peroxidation metabolites concentration, but also increased superoxiddismutase and catalase activity. Other peptides did not interfere enzyme activity. The use of DSLET or DAGO increased the superoxiddismutase plasma activity. Dynorphin A (1-13) injection increased catalase activity, but not superoxiddismutase. These effects could be explained by peculiarities of opioid receptors spread in liver tissue and stress-limiting action of peptides in entire organism.