Decreases in Glucocorticoid Sensitivity as a Factor of Stress-Producing Changes in the Activity of Monoamine Oxidase, Lipid Peroxidation, and Behavior in Rats

Abstract

Four episodes of immobilization stress induced a decrease in the sensitivity of rats to glucocorticoid hormones, which was accompanied by anxiogenic behavior, increased MAO-B activity, and a parallel increase in lipid peroxidation (LPO) in brain tissues. There was a simultaneous increase in MAO-B activity in the kidneys and accumulation of LPO products in the liver and kidneys. Administration of Kenalog (2 mg/kg), a pharmacological analog of glucocorticoid hormones, prevented the poststress activation of MAO-B and LPO and decreased the extent of anxiogenic behavioral abnormalities in rats.