[Phenoloxidase and peroxidase activity in presens of different effectors (author's transl)]

Small gut of the white rat was sectioned by the cryostat in slides of 10 microns and following effectors were investigated: KCN, sodium-diethyl-dithiocarbamate (DDC), NaF, sodium acetate, sodium pyruvate, 0.1 N HCl, 0.1 N NaOH, NaN3, and copper sulfate. Phenoloxidase is completely inhibited by DDC and HCl, incompletely by pyruvate and NaN3. Peroxidase also is completely inactivated by HCl and incompletely by NaN3. DDC has no effect on peroxidase, because a precipitate is formed. Neither of both enzyme activities is inhibited by KCN. In presence of KCN and copper sulfate an unspezific colouring of the tissue resulted in the phenoloxidase proof. Non of the investigated effectors is suitable to differentiate between phenoloxidase and peroxidase in histochemical investigations.