Generation of superoxide ion in human red blood cell lysates.

M Scarpa,P Viglino,D Contri,A Rigo

doi:10.1016/s0021-9258(18)90560-0

Abstract

The generation of superoxide ion in human red blood cell lysates was investigated by an experimental method employing Cu,Zn superoxide dismutase as O2- scavenger and EPR to probe the oxidation state of the enzyme. The average value of the O2- flux in the erythrocytes of 8 normal individuals was (2.02 +/- 0.97) X 10(-8) M S-1. A progressive saturation of the rate of O2- production was found increasing PO2, KM = 1.04 X 10(-4) M, while the autoxidation of oxyhemoglobin did not contribute significantly to the measured O2- production.

Highlights

M Cu,Zn superoxide dismutase and appearsparticularlysuitable to measure the rate of generation of superoxide ion in erythrocytes or in biological systems characterized by high absorbance or scattering
Cata-The generationof superoxide ion ihnuman red blood lase was freed of superoxide dismutase as previously described [9]
Cell lysates was investigated by anexperimental method employing Cu,Zn superoxide dismutaseas 0, scavenger andEPR to probe the oxidationstate of the enzyme

Summary

Generation of Superoxide Ion in Human Red Blood CellLysates*

From the $Laboratory of Biophysics,Institute of General Pathbgy, University of Padova, Padova, Italy, the §Institute of Physical Chemistry, University of Venice, Venice, Italy, and the TOspedali CiviliRiuniti, Venice, Italy lysates of packed human erythrocytes. These data were obtained following the rateof approach of superoxide dismutase to the steady state by EPR. This type of spectroscopy was utilized since it is far less perturbative than "F- NMR. It requires only the addition of about. M Cu,Zn superoxide dismutase and appearsparticularlysuitable to measure the rate of generation of superoxide ion in erythrocytes or in biological systems characterized by high absorbance or scattering

MATERIALS ANDMETHODS

Findings

Time of addtion of superoxide disw*