In this experiment, examined were short-term effect of alpha-2 adrenoreceptor agonist yohimbine on physiological, behavioral changes and ulceration induced by the 48 hr. conflict-stress session and compared with effect of conflict-stress
condition.
The
experimental animals were 35 rats, each of which was distributed to one of the five group: yohimbine and conflict treatment group(experimental group N=10), conflict treatment without yohimbine group(control group N=10), yoked yohimbine without
conflict
group(compared group 1 N=4), yoked conflict without yohimbine group (compared group 2 N=4) and no stress treatment group(compared group 3 N=7). The experiment was conducted for 48 hours. During the first 24 hr. session, the animals received the
feedback
of the shock termination or delay by their lever-pressing coping behavior so that could escape the stress stimulation. However, during the second 24 hr. conflict-stress session, they were provided a brief shock as a first feedback and the shock
termination or delay as the second feedback of the lever-pressing coping behavior as in the first session. In this way avoidance-avoidance conflict condition was induced experimentally. Yohimbine(2cc/kg) was administrated twice during the entire
experiment. Thus experimental group received the conflict stress and yohimbine, and control group took only conflict stress without yohimbine treatment. The compared 1 group which was yorked to experimental group received yohimbine treatment and
uncontrollable stress without conflict, compared 2 group which was yorked to control group took only uncontrollable stress without yohimbine treatment and conflict, and ocmpared 3 group did not receive any stress stimulation.
The results of the experiment were as follow. The effect of yohimbine and conflict were found in terms of stress ulceration aggravation and coping behavior decrease but not weight loss and water intake, the experimental group showed more severe
ulcerarion than the other groups. The control group showed the stress reaction in terms of coping behevior decreasment and mild level unceration. Two yoked groups also suggestd the mild level ulceration but not coping behavior.
Based on this result for this experiment, it was found that the psychological conflict induced experimentally and yohimbine had the definitive effect of the ulceration aggravaion and suggested neither psychological conflict not yohimbine
treatment
sufficient for stress ulceration nevertheless psychological conflict or uncontrollable condition or yohimbine treatment induced mild ulceration stress response.
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