STUDIES OF MECHANISMS OF CHEMICAL RADIATION PROTECTION IN VIVO. II. EFFECT OF HIGH PRESSURE OXYGEN ON RADIOPROTECTION IN VIVO AND ITS RELATIONSHIP TO 'OXYGEN POISONING'
Pure oxygen respired at 45 psi gage-pressure by rats during or immediately after whole-body x irradiation did not significantly alter LD/sub 50/ (30 days) and LD/sub 95/ (30 days) survival doses. Oxygen respired at 60 psi gage-pressure completely abolished the protective effect in vivo of histaraine and adrenalin and substantially reduced that of 5-hydroxytryptamine (5HT). The radioprotective actions of cysteamine, cystamine, 1-cysteine, and AET, were slightly reduced at 60 psi, but cyanide potentiated this reduction for cystamine and 5HT. Polarographic raeasurement of tissue oxygen-tensions for oxygen respired at pressures up to 60 psi gave a linear relation between the partial pressure of oxygen respired and the subcutaneous tissue oxygen-tension. 5HT and cystamine caused a significant reduction in the slope of this line, but this seemed insufficient to explain radiochemical protection solely in terms of pharmacologically-induced intercellular anoxia. Manometric measurements of arterial and venous blood oxygen-tensions supported the polarographic findings. Various agents which gave good protection against irradiation also protected against oxygen poisoning. However, in rats and mice, many other compounds tested gave marked protection against oxygen poisoning but failed to sffect radlosensitivity significantly. (auth)
- Research Organization:
- Radiobiological Research Unit, Cancer Inst. Board, Melbourne
- NSA Number:
- NSA-16-014589
- OSTI ID:
- 4795264
- Journal Information:
- Intern. J. Radiation Biol., Journal Name: Intern. J. Radiation Biol. Vol. Vol: 4
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
STUDIES OF MECHANISMS OF CHEMICAL RADIATION PROTECTION IN VIVO. I. 5- HYDROXYTRYPTAMINE IN RELATION TO EFFECT OF ANTIMETABOLITES, ANTAGONISTS AND RELEASING AGENTS
EFFECTS OF CERTAIN RADIO-PROTECTIVE AGENTS ON THE RADIOSENSITIVITY AND THE LEVEL OF OXYGEN IN ANIMAL TISSUES