Diabetes, Vol 46, Issue 1 133-137, Copyright © 1997 by American Diabetes Association
Effect of granulocyte-colony stimulating factor on generation of oxygen-derived free radicals and myeloperoxidase activity in neutrophils from poorly controlled NIDDM patients
N Sato, K Kashima, Y Tanaka, H Shimizu and M Mori
First Department of Internal Medicine, Gunma University School of Medicine, Maebashi, Japan.
To evaluate whether granulocyte-colony stimulating factor (G-CSF) improves
an impaired production of oxygen-derived free radicals by neutrophils from
poorly controlled NIDDM patients, we studied the effect of G-CSF on
myeloperoxidase (MPO) activity and chemiluminescence amplified by a
Cypridina luciferin analog (CLA-DCL), which is dependent on O2 generation,
and luminol (L-DCL), which is dependent on OCl(-) generation, in response
to formyl-methonyl-leucyl-phenylalanine. Both CLA-DCL and L-DCL by
neutrophils from the diabetic group (n = 15, HbA(1c) >10%) were
significantly decreased (26 and 37%, respectively: P < 0.01) compared
with the age-matched normal control group (n = 15), and L-DCL was more
sensitive to this inhibition than CLA-DCL (P < 0.05). In both control
and diabetic neutrophils, G-CSF significantly enhanced both CLA-DCL (175%
in control and 156% in diabetic) and L-DCL (283% in control and 346% in
diabetic). In diabetic neutrophils, the enhancing effect of G-CSF on L-DCL
was more sensitive than on CLA-DCL (P < 0.001). There was a positive
correlation between HbA(1c) and the enhancing effect of G-CSF on L-DCL in
diabetic patients (P < 0.05), but not on CLA-DCL. MPO activity was also
decreased in the diabetic group (63%, P < 0.05), and G-CSF improved this
impaired MPO activity (184%, P < 0.01). Furthermore, there was a
positive correlation between HbA(1c) and the improving effect of G-CSF on
MPO activity (P < 0.05). Because bacterial infection still accounts for
an important cause of morbidity and mortality in diabetic patients, these
data suggest that G-CSF may be useful as a drug to prevent the aggravation
of bacterial infection by improving neutrophil function, especially through
H2O2-MPO-OCl(-) mechanism, in poorly controlled diabetic patients.