Levels of Corticosterone and Glucose in Blood of Rats under Conditions of Chronic Unpredictable Stress of Different Duration

Abstract

INTRODUCTION: Mammals are almost constantly exposed to a variety of stressors. The changes in the concentration of corticosterone and the level of glucose in blood of animals under such conditions seems relevant for understanding the influence of repeated stress effects on endocrine and metabolic processes. AIM: To study the concentrations of corticosterone and glucose in blood of rats in different time periods of prolonged low-intensity unpredictable stress. MATERIALS AND METHODS: Experiments were carried out on 42 male Wistar rats. Individuals of the experimental groups were subjected to 7-day cycles of alternating stressors using a modified model of chronic unpredictable mild stress with presentation of different stressors. The concentration of corticosterone and glucose in blood was determined at 1, 2, 3 and 4 weeks of observation. RESULTS: A pronounced decrease in corticosterone levels was found in rats at 1 week of stress exposure, followed by a slow recovery by the end of 4th week. Blood glucose level increased at 2 weeks of exposure. CONCLUSION: The data obtained illustrate the specificity of changes in the levels of glucose and corticosterone in the blood of mammals in different time periods of chronic stress. These changes characterize the dysregulation of the integrative physiological systems in relatively early periods of chronic stress with the subsequent development of adaptation in the later stages of repeated stress exposures.