Paramecium tetraurelia growth stimulation under low-level chronic irradiation: investigations on a possible mechanism. [/sup 60/Co]

Journal Article · Wed Dec 01 04:00:00 EST 1982 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575928· OSTI ID:6170654

Croute, F; Soleilhavoup, J P; Vidal, S; Dupouy, D; Planel, H

Experiments were carried out to demonstrate the effects of low-level chronic irradiation on Paramecium tetraurelia proliferation. Biological effects were strongly dependent on the bacterial density of culture medium and more exactly on the catalase content of the medium. Significant growth stimulation was found under /sup 60/Co chronic irradiation at a dose rate of 2 rad/year when paramecia were grown in a medium containing a high bacterial concentration (2.5 x 10/sup 2/ cells/m) or supplemented with catalase (300 U/ml). In a medium with a low bacterial density (1 x 10/sup 6/ cell/ml) or supplemented with a catalase activity inhibitor, growth simulation was preceded by a transitory inhibiting effect which could be correlated with extracellularly radioproduced H/sub 2/O/sub 2/. H/sub 2/O/sub 2/ addition appeared to be able to simulate the biological effects of chronic irradiation. A possible mechanism is discussed.We proposed that the stimulating effects were the result of intracellular enzymatic scavenging of radioproduced H/sub 2/O/sub 2/.

• Research Organization: Univ. Toulouse III, France
• OSTI ID: 6170654
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 92:3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560131* -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CELL PROLIFERATION
CHRONIC EXPOSURE
CHRONIC IRRADIATION
CILIATA
COBALT 60
COBALT ISOTOPES
ELECTROMAGNETIC RADIATION
GAMMA RADIATION
GROWTH
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
INVERTEBRATES
IONIZING RADIATIONS
IRRADIATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LOW DOSE IRRADIATION
MICROORGANISMS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
OXYGEN COMPOUNDS
PARAMECIUM
PEROXIDES
PROTOZOA
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
STIMULATION
YEARS LIVING RADIOISOTOPES