The induction of reciprocal translocations in mouse germ cells by chemicals and ionizing radiations. III. Differential effect of two doses of adriamycin combined with 5 or 9 Gy of gamma-rays

J.C. DE LUCA; F.N. DULOUT; C.A. GRILLO; N.C. TERREROS; J.M. ANDRIEU

MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 1990

0027-5107

The induction of reciprocal translocations in mouse germ cells by combined treatments with chemicals and ionizing radiations has been studied. Male mice were intraperitoneally injected with doses of 5 or 10 mg/kg of adriamycin (ADR) and irradiated with doses of 5 or 9 Gy of gamma-rays 24 h later. Three types of response were found after analyzing diakinesis-metaphase I multivalent configurations: potentiation, with the dose of 5 mg/kg of ADR plus 9 Gy; subadditivity, with the dose of 5 mg/kg of ADR plus 5 Gy; and additivity, with the dose of 10 mg/kg of ADR plus 5 or 9 Gy. According to these results, the subadditive effect observed with the lower dose of ADR plus 5 Gy cannot be explained under the assumption that depletion of any kind of spermatogonia is sufficient for modifying the chromosomal response of stem cells to ionizing radiations. The role of DNA repair mechanisms modulating the response of spermatogonial cells to combined treatments is discussed under the assumption that some repair mechanisms can be triggered by treatment with a low dose of a chemical and these repair mechanisms can reduce cell mortality. Consequently, a higher frequency of more radioresistant cells can survive.