Effect of Some Dithiocarbamates on Respiration Activity of a Myxomycete.

The present article aims at giving some information concerning the mode of action of three dithiocarbamates: ferric dimethyldithiocarbamate (Ferbam), zinc dimethyldithiocarbomate (Ziram) and tetramethylthiuram disulfide (Thiram). These inhibitors were tested on the respiratory activity of the Myxomycete: Physarum polycephalum. Its development is strongly inhibited at 285 mg/l. With such concentration, respiration measurements confirmed total inhibition of O₂ uptake. After isolation of the mitochondria, the tests showed that there may be an inhibition of the succinic oxidase activity of this particulate fraction, at 28.5 mg/l of Thiram. Heavy concentration of reduced glutathione (1.4%) reversed partially this inhibition. This seems to prove that succinic dehydrogenase is a typical SH-type enzyme. [ABSTRACT FROM AUTHOR]