CYSTEINE PROTECTION AGAINST X-RAYS AND THE FACTOR OF OXYGEN TENSION

Journal Article · Mon Aug 01 04:00:00 EDT 1960 · Radiation Research

DOI:https://doi.org/10.2307/3570957· OSTI ID:4165606

Kohn, H I; Gunter, S E

Protection experiments were carried out with washed suspensions of Escherichia coli B/r that were suspended in buffer, exposed to 0.1 M I-cysteine at 22 to 24 eC, and then irradiated with 250-kv x rays at 0 deg C. Trials were made with suspensions in equilibrium with 0, 5, 20, and 100% oxygen at the time of irradiation, at pH 5 and at pH 7.8. I-Cysteine afforded significant protection under all conditions. The mode of action of cysteine therefore includes one reaction that can occur independently of oxygen. The independence is both biologic and radiologic; i.e., oxygen is not needed for cysteine to reach the sensitive locus prior to irradiation, nor is it needed at the time of irradiation. It was also shown in tests at pH 7.4 to 7.8 that the ethyl ester of I-cysteine and d-cysteine protect under anoxic conditions; d-cysteine, however, was significantly less potent than I-cysteine at pH 5. (auth)

• Research Organization: Univ. of California, School of Medicine, San Francisco
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-021333
• OSTI ID: 4165606
• Journal Information: Radiation Research, Journal Name: Radiation Research Vol. Vol: 13
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACIDITY
BACTERIA
BIOLOGY AND MEDICINE
CYSTEINE
ESCHERICHIA COLI
OXYGEN
QUANTITY RATIO
RADIATION PROTECTION
SUSPENSIONS
TEMPERATURE
X RADIATION