[Metabolic transformation of antibiotics of the tetracycline series in peroxidase reactions].

In was shown calorimetrically that in the presence of horse radish peroxidase tetracyclines induced degradation of hydrogen peroxide. Under such conditions changes in the tetracycline optical properties were detected photometrically. It was concluded that tetracyclines were metabolized in the peroxidase reactions catalyzed by horse radish peroxidase as their substrates. The tetracycline peroxidase oxidation was catalyzed not only by horse radish peroxidase but also by methemoglobin possessing the peroxidase activity. In the experiments with ascorbate there were detected characteristic peculiarities of the tetracycline peroxidase oxidation catalyzed by both horse radish peroxidase and methemoglobin. These peculiarities made it possible to classify the tetracyclines as the substrates of the peroxidase reaction belonging to the oxidogenic group. The fact that tetracyclines can be metabolized in peroxidase reactions is discussed in regard to its possible influence on their mechanism of antibacterial action and the development of tetracycline resistance.