Membrane alterations in G6PD- and PK-deficient erythrocytes exposed to oxidizing agents.
After in vitro treatment of normal, glucose-6-phosphate dehydrogenase-deficient or pyruvate kinase-deficient human erythrocytes with three different oxidizing agents, the extent of lipid peroxidative degradation and the alterations of membrane proteins were evaluated. Exposure to tert-butylhydroperoxide induced, most markedly in G6PD- and PK-deficient erythrocytes, a reduction of protein bands 1, 2, 2.1, 3, 4.1, 4.2, and 5, with the appearance of high-molecular-weight aggregates and of "new" polypeptide components in the 29- to 23-kDa region and with a marked increase of membrane-bound globin. Malonyldialdehyde production was highest in G6PD-deficient cells and relatively low in PK-deficient ones. Methylene blue, which had similar but less relevant effects on lipid peroxidation, in G6PD-deficient erythrocytes caused a conspicuous appearance of high-molecular-weight aggregates and a simultaneous relevant decrease of bands 1 and 2 and of membrane-bound globin; it brought about an almost opposite effect in PK-deficient red cells. Acetylphenylhydrazine, which under our conditions appeared the mildest agent, failed, in normal and PK-deficient erythrocytes, to increase malonyldialdehyde production or to alter membrane proteins, whereas it caused, in G6PD-deficient cells, a slight decrease of bands 1 and 2, a more pronounced decrease of band 3, and a marked increase of bands 4.5 and 4.9.
Caprari
P
P
Laboratori di Biochimica Clinica, Istituto Superiore di Sanità, Rome, Italy.
Bozzi
A
A
Ferroni
L
L
Giuliani
A
A
La Chiusa
B F
BF
Strom
R
R
Salvati
A M
AM
D004910:Erythrocyte Membrane / Q000187:drug effects; D004912:Erythrocytes / Q000201:enzymology*; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects; D008565:Membrane Proteins / Q000097:blood; D008751:Methylene Blue / Q000494:pharmacology; D010545:Peroxides / Q000494:pharmacology; D010659:Phenylhydrazines / Q000494:pharmacology; D011770:Pyruvate Kinase / Q000097:blood / Q000172:deficiency*; D020122:tert-Butylhydroperoxide
D008565:Membrane Proteins; D010545:Peroxides; D010659:Phenylhydrazines; D020122:tert-Butylhydroperoxide; C006384:N(1)-acetylphenylhydrazine; D011770:Pyruvate Kinase; D008751:Methylene Blue