Peroxidase activity in human granulocytes, inter- and intra-individual variations

Abstract

A kinetic method for quantitation of peroxidase activity (‘myeloperoxidase’, E.C.1.11.1.7.) in human granulocytes has been evaluated. The enzymic activity was determined at 37d`C, pH = 7.0. Substrates: 2-methyxo-phenol (1.25 mmol/l) and H₂O₂ (0.1 mmol/1). When applied on granulocytes from solitary blood samples from healthy, normal subjects the detected peroxidase activity varied considerably from one person to another (CV = 40–50%). Sequential determinations of the peroxidase activity in granulocytes from selected healthy, normal subjects demonstrated substantial intra-individual variations. Analysis of variance confirmed that the intra-individual variations (CV = 36%) exceeded all other variance components involved.