Effect of 3-aminobenzamide on chromosome damage in human blood lymphocytes adapted to bleomycin

Abstract

Human blood lymphocytes, pre-treated with very low (adaptation) concentrations of bleomycin for 48 h and then exposed to a high (challenge) dose of the same agent or X-rays, became significantly less sensitive to the induction of chromosome damage than those which did not receive the pre-treatment, indicating an induction of 'adaptive repair' process. This repair process was negated when 3-aminobenzamide, an inhibitor of poly (ADP) polymerase, was added to the cultures immediately after the challenge treatment. The magnitude of negation in the adaptation response was greater in the case of lymphocytes challenged with X-rays as compared with those challenged with bleomycin.

Adaptive Response in Mice Exposed to 900 MHz Radiofrequency Fields: Primary DNA Damage

“…Perhaps, RF exposure given as AD produces a ‘signal or trigger’ that does not induce significant genetic damage but offers protection to subsequent damage induced by genotoxic CD. Several other hypotheses have been proposed in the case of IR-induced AR: these include and not limited to efficient repair of damaged DNA, potential role for DNA repair enzymes and protein synthesis [23]–[28]. In this study, we have observed a significant reduction in primary damage in mice exposed to AD+CD.…”

Treatment with 3-Aminobenzamide Negates the Radiofrequency-Induced Adaptive Response in Two Cell Models

“…MMC (Sigma, St. Louis, MO, USA) was dissolved in sterile distilled water, and given at 48 h (100 ng/mL) or 32 h (500 ng/mL) after seeding, for HPBL and V79 cells, respectively. 3AB (Sigma, St. Louis, MO, USA) was dissolved in dimethyl-sulfoxide (DMSO, Lab-Scan Analytical Science, Dublin, Ireland), and given at 48 h (HPBL) or 32 h (V79 cells) at a final concentration of 2 mM, according to the procedure reported in the literature for several cell types [15,24]. To block cytokinesis, cytochalasin-B (Sigma, St. Louis, MO, USA; dissolved in DMSO) was added at a final concentration of 6 µg/mL at 44 h after PHA stimulation in HPBL cultures, and at 3 µg/mL at 28 h after seeding in V79 cultures.…”

The cell dose concept; potential application in radiation protection

“…This is a testimony to improved repair in pre-irradiated cells over the given period of time. These data have been reproduced (Vijayalaxmi and Burkart 1989) and indicate that adaptive responses of cells obviously alter the probability of risk regarding chromatid aberrations.…”