Mutagenicity of dimethylsulfoxide (DMSO): in vivo cytogenetics study in the rat

Various concentrations (1%, 10%, 50%, and 100%) of laboratory grade dimethylsulfoxide (DMSO) were administered by intraperitoneal injection to male Sprague-Dawley rats for five consecutive days. Femoral bone marrow cells were harvested 24 hours after the last injection and were analyzed for cytogenetic aberration frequencies including chromosome breaks, chromatid breaks, markers, and severely damaged cells. Chromosome breaks revealed no differences between treated and control groups. Chromatid breaks were significantly elevated over the controls in all treated groups except at the 10% level. The incidence of markers was significantly elevated when compared to the controls in all treated groups. Only the high-level (100%) group showed a significant increase in the incidence of severely damaged cells. When the above data were combined, the resultant percent of aberrant cells per animal was found to increase from 10% aberrant cells at the 1% DMSO level to 68.67% aberrant cells at the 100% DMSO level. The incidences of aberrant cells in all treated groups were significantly elevated when compared to the control (4% aberrant cells) group. These observations suggest that DMSO effectively disrupts the integrity of rat chromosome structure, and further investigation of the genetic activity of DMSO is warranted.