ABSTRACT
Background: In this study; the effect of cold and haemorrhagic stressors in male albino Wistar rats will be investigated. Methods: Cold stress was induced by placing the animals in thermostatic chamber containing ice cold water (0-10oC) and well aerated. Rats were allowed to stay for 5; 10; 15 and 20 minutes before they were bled from the tail vein at 2; 4; 6; 8 and 24 hours for reticulocyte counts. For the haemorrhagic stress; 30of blood was withdrawn from the vein after which reticulocytes were counted at 2; 4; 6; 8 and 24 hours. Results: Cold and haemorrhagic stress caused increased reticulocyte counts in male albino Wistar rats. The controls were not subjected to any condition. In cold stress; the maximum percentage reticulocyte count was (at zero hour) 6.21 + 0.21while the control was 1.02 + 0.12. In the case of the haemorrhagic stressor; the percentage reticulocyte was seen to peak at the 6th hour (6.19 + 0.12) and subsequently decrease to 2.59 + 0.02. The probable causes of this rise in reticulocytes are discussed. Conclusion: In cold and haemorrhagic stress; reticulocyte count peaked at 2 and 6 hours respectively; depicting when maximum erythropoietic activity was reached in blood forming organs