Effects of chronic unpredictable stress on intestinal morphology in Wistar rats

Abstract

Stressful events might cause immune dysfunction and trigger various disorders. Adverse effects of acute orchronic stress exposure on the gastrointestinal system have been shown previously in several studies. In this experimentalstudy, we used chronic unpredictable stress (CUS) paradigm to better mimic effects of the intermittent exposure to daily lifestress and investigated the morphometric alterations occurring in the small intestines of rats.Methods: Male Wistar rats were randomly divided into stress and control groups (n=8, each). While stress group was subjected to chronic unpredictable stress protocol for 21 days, control group remained undisturbed. Intestinal tissue sampleswere obtained from two different regions; one was 3-6 cm away from the pylorus and the other one 3-6 cm prior to theileocaecal valve. Tissue sections were obtained from paraffin blocks at the thickness of 3 micrometers and stained withhematoxylin-eosin (HE) or periodic acid-Shiff (PAS). The lengths of villi were measured from the basal membrane to the topof the villus. The ratio of degranulating and non-degranulating mast cells per unit area were estimated by point countingmethod.Results: The mean villi length in the stress group were significantly higher (p