The mechanism of stress and immunosuppression

The effects of stress on the central nervous system, endocrine balance and immunity were observed in male Sprague-Dawley rats. Food and water were supplied in unlimited quantities. Extraneous odors were kept away from the control room by an exhaust fan in the adjacent room. At 70 days, experimentation occured for 20 days. In the aspirin, parathroid, serotonin, and pineal groups, there was no significant difference between the undistrubed control and experimental groups. A significant reduction in both the pituitary and adrenal weights was seen in the melatonin experimental group and the undisturbed control group. The placebo control group showed a significant increase in both the pituitary and adrenal gland weights. Stress was blocked in the groups receiving aspirin, parathroid, serotonin, and pineal preparations. The melatonin group, however, very significantly blocked the stress in that both the pituitary and adrenal weights were significantly below the undisturbed control group. The aspirin blocked stress by inhibiting synthesis of prostaglandins. Melatonin works through the pituitary-adrenal axis to reduce adrenal secretion.