Effect of immobilization stress on scratching behavior in male rat

Stress is one of the most psychological disorders that can lead to many health problems, including vascular diseases of heart and brain, cancers and immunity suppression. Since it has been reported that there is a relationship between stress and skin inflammation in one hand, and inflammation and scratching on the other hand, in the present study the effect of immobilization stress has been investigated on skin scratching. In this experimental study, 26 male rats were randomly divided into control and case groups. Stress was induced in the case animals, two hours daily for five days. After inducing stress in each day, animals were observed for one hour and their scratching behavior was determined. The weight and scratching behavior were assessed before and 24 hour after the experiment. At the end of the examination, WBC counts were evaluated. The mean frequency of scratching in days 1 and 2 was higher in the case group than the control group, but this difference was not found significant. However, in case group, mean frequency of scratching was significantly higher on day 3 (P<0.05), day 4 (P<0.01) and day 5 (P<0.001) compared to the control group. Our data showed that immobilization stress may lead to increase in skin scratching.