The relationship between catalase and haemoglobin in human blood

Abstract

A simple titrimetric method, giving reproducible results, is described for estimating the catalase activity of blood. The results are expressed in arbitrary units which can readily be converted into the conventional Kat. f. units. The principle of this method depends upon the destructive effect which H2O2 has upon the enzyme, and the quantities are arranged so that the catalase is destroyed before all the substrate has been decomposed. The reaction may therefore be allowed to proceed to completion and the time factor is no longer critical when making the actual measurements. Under these conditions, there is a linear relationship between the amounts of substrate finally utilized and the quantity of enzyme present. There is a constant relationship between catalase activity and hemoglobin concentration which is not affected by anemia, age or sex. It is suggested that this relationship indicates a common metabolic pathway for the formation of hemoglobin and catalase, so far as the hematin part of the molecule is concerned.