In vivo genotoxic effects of spiramycin in rat bone marrow cells

The aim of this study was to investigate the genotoxic effects of spiramycin which is an effective ingredient of the antibiotic rovamycine in bone marrow cells of rats (Rattus norvegicus var. albinos). The rats were treated with 100, 200, 400 mg/kg bwt/day of spiramycin. Animals were treated with the above concentrations for 7 days and the bone marrow preparations were prepared after 6 and 12 h from the last administration. In 100 mg/kg bwt/day, spiramycin increased the percentages of the abnormal cells and the chromosomal aberration per cell (CA/cell) in the bone marrow cells of rats that were sacrificed after 6 h from the last administration. It could not induce the abnormalities however at the other concentrations (200 and 400 mg/kg bwt/day). The mitotic index (MI) was not decreased by any treatment of spiramycin. Spiramycin did not increase neither the percentage of abnormal cells nor the CA/cell in bone marrow cells of rats which sacrificed after 12 h from the last administration, whereas it generally decreased the MI in this treatment. Spiramycin did not affect the formation of chromosomal gaps.