EFFECTS OF HYPERTHERMIA ON AVIAN RED-BLOOD-CELLS

Our primary goal was to develop a model for studying the effects of he at on terminally differentiated cells. Using nucleated chicken red blo od cells (RBC) as the model, heat dose-response and thermotolerance we re investigated. A new haemolytic assay was developed to score them. H eating chicken RBC for as long as 3 h at 51.5-degrees-C resulted in on ly small amounts of haemolysis immediately after heating. When haemoly sis was scored 1-2 days after heating, heat-induced haemolysis increas ed with heating temperature and duration. Heat shock of 30-90 min at 4 2.6-degrees-C just before heat challenge of 40 min at 51.5-degrees-C, or heat shock of 15 min at 43.1-degrees-C with incubation of 0-2 h at 35-37-degrees-C prior to the same heat challenge induced thermotoleran ce, but the levels of heat resistance achieved were different. Similar experiments were performed using potassium leakage as the endpoint. P otassium leakage was measurable immediately after heating, and it incr eased with heating duration, but there was no correlation between pota ssium leakage and haemolysis. Potassium leakage was not a suitable cri terion for measuring thermotolerance.