title: Thermal sensitivity and kinetics of thermotolerance in bovine aortic endothelial cells in culture.
abstract: The effect of heat on the clonogenicity of bovine aortic endothelial (BAE) cells in vitro was measured. Continuous heating of cells at 43 degrees C or 43.5 degrees C produced survival curves exhibiting thermoresistant tails. When heated at 44 degrees C the survival curve of BAE cells was exponential except for a small shoulder. The BAE cells heated at 44 degrees C and 45 degrees C had D0 values of 33 min and 19 min, respectively. The development of thermotolerance in BAE cells was studied by measuring the sensitivity of cells to a 44 degrees C heating at various times following a priming heat treatment at 43 degrees C or 44 degrees C for 30 min. The thermotolerance ratio in BAE cells preheated at 43 degrees C for 30 min reached a peak of 3.8 at 3 h and declined to 1.9 at 24 h after the prime heating. After prime heating at 44 degrees C for 30 min the thermotolerance ratio increased rapidly to 5.4 in 5 h, remained elevated at 12 h and then declined to a value of 2.1 at 24 h. Thermotolerance in endothelial cells may be partially responsible for the thermotolerance in blood vessels of normal tissues and tumours.
authors.affiliation: University of Minnesota Medical School, Department of Therapeutic Radiology-Radiation Oncology, Minneapolis 55455.
authors.forename: S K
authors.initials: SK
authors.lastname: Sahu
authors.forename: C W
authors.initials: CW
authors.lastname: Song
mesh_terms: D000818:Animals; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D002999:Clone Cells / Q000166:cytology; D004730:Endothelium, Vascular / Q000166:cytology / Q000293:injuries*; D006358:Hot Temperature / Q000009:adverse effects*; D007700:Kinetics