Comparison of the effects of acute and chronic psychological stress on metabolic features in rats

This study was aimed to compare the effects of acute and chronic psychological stress on metabolic factors. Forty-two male Wistar rats were divided into control and stressed groups. Stress was applied by a commu- nication box acutely （1 d） and chronically （15 and 30 d）. Blood sampling was carried out by retro-orbital-puncture method. The plasma levels of glucose, cholesterol, triglyceride, insulin, and corticosterone were measured. In addition, feed and water intake, latency to eat and drink, adrenal and body weights were determined. Acute and chronic psy- chological stress did not significantly change basal plasma corticosterone levels. However, immediately （1 min） after acute exposure to stress, plasma corticosterone level increased compared to that before stress exposure. Acute stress increased plasma insulin levels significantly. Fifteen days of stress exposure resulted in plasma glucose increase. Chronic stress significantly increased feed intake, latency to eat, and adrenal weight compared to acute stress. The body weights of both control and stressed groups increased markedly during the experiment. Homeostasis model assessment of insulin resistance （HOMA-IR） index did not change significantly in the stressed group. In conclusion, application of acute and chronic psychological stress leads to different metabolic and/or behavioral changes but the metabolic changes resulting from acute exposure to stress seem to be more pronounced.