Comparative study of different types of stress on some physiological and biochemical parameters in albino rats

Effects of one day, 7 days and of 15 days of fresh water swimming and cold water swimming and the effect of 7 days, 15 days and 30 days of isolation, immobilization and overcrowding stress was studied in Wistar strain albino rats. The different physiological parameters considered were body weight, liver, heart, brain and adrenal weight, total leucocyte count, eosinophil, lymphocyte and neutrophil counts. In the biochemical parameters, the effect on blood sugar, total serum cholesterol and serum transaminase levels were studied. There was a significant decrease in the whole body mass after 7 days of stress. A significant increase in the weight of liver, heart, brain and adrenals was also observed. Total leucocyte number decreased significantly and also there was significant eosinopenia, lymphocytopenia and neutropenia. In all the five stress types, a significant decrease in blood sugar and serum cholesterol level was observed. There was a significant increase in serum transaminase (SGOT and SGPT) levels in all the subgroups. The gradual reduction observed in the physiological stress response after 15 and 30 days of stress could be due to the habituation of the hypothalamo- pituitary adrenal axis when the same stress was repeated for a long time. A short session of stress or acute stress also produced a significant physiological and biochemical changes in the animals. The response to acute physical stress like forced swimming, appeared to be more effective than the response to acute psychological stressor like isolation, in the initial stages at least. A profound long lasting biochemical changes were there to a repeatedly applied stressor.