Effect of Dichloroglyoxime and Dimethylglyoxime on the Acellular Slime Mold Physarum polycephalum PDF

Keywords

cytoplasm, slime mold, dichloroglyoxime, dimethylglyoxime

Abstract

The effect of different concentrations of dichloroglyoxime (DCG) and dimethylglyoxime (DMG) on the cytoplasmic shuttle streaming (in vivo) and on the contraction-relaxation activity of excised plasmodial strands (in situ) were investigated. In the concentration range between 0.5- 2 µg/ml, DCG caused disturbances and subsequent stop of cytoplasmic streaming. Higher concentrations induced a direct and rapid stop of cytoplasmic streaming followed by contraction of the whole plasmodium, blebbing and disintegration of plasma membrane. These effects were completely irreversible. Concentrations of DCG ≤ 0.5 µg/ml induced concentration of excised plasmodial strands measured tensiometrically under isometric conditions. A concentration dependent decrease in frequency of the contraction-relaxation cycle, but an increase in force amplitude were observed. A concentrations of DCG ≥ 2.0 µg/ml caused a single, very strong contraction followed by an irreversible relaxation. DMG did not induce obvious effects on migrating plasmodium or cytoplasmic streaming. When applied to isometrically oscillating excised strands of Physarum, DMG showed a concentration-dependent decrease in oscillation frequency. These results showed that some glyoxime derivatives (even in micromolar concentrations) have cytotoxic effects. Further investigations should be done before recommending such derivatives as commercial disinfectants.