Effect of immobilization stress on food intake, body weight and weights of various organs in rat.

Effect of immobilization stress was studied in male albino rats. Experimental rats (E) were restrained in close-fitting wiremesh cylinders. Control rats (C) were not subjected to restraint. Food and water were made available to C for all the 24 hrs while the E were given them for only 6 hrs daily. The initial lower food intake of E was later reversed to near normal levels. There was a steady fall in the body weights of E, while the C displayed a normal growth rate. Cerebrum, cerebellum, pituitary and adrenals of E weighted significantly more. There was an apparent increase in the weight of thyroid. Gonads displayed no change in weight. The results indicate that chronic restraint causes loss of body weight inspite of a near normal food intake. It also produces an increase in the weight of brain, and certain endocrine organs.