Nitrite and nitroso compounds can serve as specific catalase inhibitors.

Objective: We present evidence that nitrite and nitrosothiols, nitrosoamines and non-heme dinitrosyl iron complexes can reversibly inhibit catalase with equal effectiveness.

Methods: Catalase activity was evaluated by the permanganatometric and calorimetric assays.

Results: This inhibition is not the result of chemical transformations of these compounds to a single inhibitor, as well as it is not the result of NO release from these substances (as NO traps have no effect on the extent of inhibition).