THE EFFECT OF CUPFERRON, CARBON MONOXIDE, AND 2.4-DINITROPHENOL ON THE PRODUCTION OF CHROMOSOMAL ABERRATIONS BY X-RAYS IN VICIA FABA

Journal Article · Mon Jan 01 00:00:00 EST 1962 · Abhandl. Deut. Akad. Wiss. Berlin, Kl. Med.

OSTI ID:4646673

Kihlman, B A

The effects of cupferron, carbon monoxide, and 2.4dinitrophenol (DNP) on the frequencies of chromatid aberrations produced by x rays in the root-tips of Vicia faba were studied. At an oxygen concentration of 1%, in the gas phase, cupferron and carbon monoxide produced ~ strong increase in the frequencies of aberrations when they were present before and during irradiation. No enhancement was obtained when the inhibitor treatments were applied immediately after the x- ray irridiation. These results agree with the idea that respiratory innibitors enhance the x-ray sensitivity of bean roots at low oxygen tensions because they prevent the formation of an oxygen gradient in the roots. In contrast to the cupferion effect, the enhancement produced by carbon monoxide was sensitive to light and occurred only in the dark. At a dose rate of 6.4 r/min. and at an oxygen tension of 100% in the gas phase, both cupferron and DNP enhanced considerably the frequency of chromatid interchanges produced by a given dose of x rays. When the dose rate was increased to 120 r/min., the effect obtained in the absencc of the inhibitors increased, whereas that obtained in their presence remained constant. As a consequence, the enhancement produced by the inhibitors at low dose rates disappeared completely (cupferron) or was markedly reduced (DNP) at high dose rates. In contrast to cupferron, DNP did not produce a strong enhancement of the x-ray effect it low oxygen tensions (2% in the gas phase). The enhancement produced by cupferron in the presence of 2% oxygen, was obtained both at low and high dose rates and was equally strong for all types of aberrations. It was concluded that the very strong enhancement of the x-ray effect which cupferion produced at low oxygen tensions is due to its inhibitory effect on respiration. The ineffectiveness of DNP in these experiments indicates that phosphorylation is not involved. The results obtained are in agrerment with the idea that cupferron enhances the effect of x rays by eliminating an oxygen gradient, which is supposed to exist in the roots at low oxygen tensions. In contrast to the strong enhancement of the x-ray effect produced by cupferron at low oxygen tensions, the considerably less marked enhancement obtained at high oxygen tensions and low dose rates could be due to the inhibitoiy action of cupferion on oxidative phosphorylation. The finding that DNP acts in the same way as cupferron in these experiments is in agreement with this interpretation. The effect of cupferion and DNP on x-ray, induced chromosome damage at high oxygen tension appears to be mainly that they cause the dose rate effect to disappear. This is in agreement with the ideal that oxidative phosphorylation is needed for the repair of chromosome damage. (auth)

• Research Organization: Uppsala Univ.
• NSA Number: NSA-17-040562
• OSTI ID: 4646673
• Journal Information: Abhandl. Deut. Akad. Wiss. Berlin, Kl. Med., Vol. Vol: No. 1; Other Information: Orig. Receipt Date: 31-DEC-63
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
AMINES
BEANS
BIOCHEMISTRY
CARBON MONOXIDE
CEREALS
CHROMOSOMES
CONFERENCE
CUPFERRON
DNP
EFFICIENCY
IRRADIATION
LIGHT
MUTATIONS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
OXYGEN
PHENOLS
PHOSPHORYLATION
PLANTS
RADIATION DOSES
RADIATION EFFECTS
RADIATION INJURIES
RADIOSENSITIVITY
REACTION KINETICS
RECOVERY
VARIATIONS
VEGETABLES
VICIA
VICIA FABA
X RADIATION