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 (B AE) cells in vitro was measured. Continuous heating of cells at 43°C or 43–5°C produced survival curves exhibiting thermoresistant tails. When heated at 44°C the survival curve of BAE cells was exponential except for a small shoulder. The BAE cells heated at 44°C and 45°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°C heating at various times following a priming heat treatment at 43°C or 44°C for 30 min. The thermotolerance ratio in BAE cells preheated at 43°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°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 endotheliaJanuary-February 1991 cells may be partially responsible for the thermotolerance in blood vessels of normal tissues and tumours.

Key Words:

• Endothelial cells
• hyperthermia
• thermosensitivity
• thermotolerance
• in vitro