CYTOLOGICAL EFFECTS OF PHENYLNITROSAMINES. III. THE EFFECT ON X-RAY SENSITIVITY AT LOW OXYGEN TENSIONS

Journal Article · Fri Sep 01 04:00:00 EDT 1961 · Radiation Botany

DOI:https://doi.org/10.1016/S0033-7560(61)80006-9· OSTI ID:4840630

Kihlman, B A

A number of agents structurally or functionally related to cupferron were studied for their ability to enhance the frequency of chromosomal aberrations produced by x rays in the presence of 1% oxygen in the root-tips of Vicia faba. A marked enhancement was obtained only with agents which inhibited bean-root respiration. In experiments with the respiratory inhibitor carbon monoxide, the x ray dose necessary to produce a given frequency of aberrations in the absence of oxygen was about 2.3 times as high as that which produced the same effect in the presence of 1% oxygen. The carbon monoxide effect was light- reversible; no enhancement was obtained when the roots were exposed to strong light during irradiation and carbon monoxide treatment. Both cupferron and carbon monoxide enhanced x raysensitivity only when they were present before and during irradiation. Post-treatments with these agents did not have any influence on the frequency of aberrations produced by a given x ray dose. The frequency of aberrations produced by 108 r of x rays was almost doubled when the change from 1% oxygen in nitrogen to 1% oxygen in carbon monoiide was made 70 sec before irradiation. In order to be fully effective, the CO-treatment was started between 2 and 5 min before irradiation. These results support the hypothesis that cupferron and other respiratory inhibitors enhance the x ray sensitivity of bean roots at low oxygen tensions because they prevent the formation of an oxygen gradient in the roots. A comparison between the cytological and physiological effects of cupferron, and those of some other agents which are structurally or functionally related to it, is presented in tabular form. (auth)

• Research Organization: Univ. of Uppsala
• Sponsoring Organization: USDOE
• NSA Number: NSA-15-030492
• OSTI ID: 4840630
• Journal Information: Radiation Botany, Journal Name: Radiation Botany Vol. Vol: 1: No. 1
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

AMINES
BIOLOGY AND MEDICINE
CARBON MONOXIDE
CHROMOSOMES
CUPFERRON
OXYGEN
PLANT CELLS
PLANTS
QUANTITY RATIO
RADIATION DOSES
RADIATION EFFECTS
RADIOSENSITIVITY
ROOTS
X RADIATION