Different effects of glucose on extracellular and intracellular respiratory burst response in normal human neutrophils activated with the soluble agonist fMet-Leu-Phe.
OBJECTIVE
The study evaluated the effects of glucose concentration on the extracellular and intracellular activation of the respiratory burst in fMet-Leu-Phe-stimulated normal human neutrophils.


METHODS
Specific extracellular respiratory burst activity was measured as superoxide dismutase (SOD)-inhibitable cytochrome c reduction. Intracellular respiratory burst activity was studied using luminol-enhanced chemiluminescence in the presence of SOD and catalase, to quench extracellular chemiluminescence activity. Myeloperoxidase (MPO) release from activated neutrophils was studied by using the guaiacol technique.


RESULTS
The extracellular respiratory burst following activation with 1 microM fMet-Leu-Phe was significantly reduced at 15 and 25 mM D-glucose (9.5 +/- 1.0 and 8.5 +/- 0.8 nmol/10(6) cells and 10 min; P < 0.01 and P < 0.001, respectively) as compared with that at 5 mM glucose (10.3 +/- 1.0 nmol/10(6) cells and 10 min). When specifically studying the intracellular respiratory burst, no difference was found between the responses at 5, 15 or 25 mM glucose. Increasing glucose concentrations also reduced the secretion of MPO from fMet-Leu-Phe-activated neutrophils.


CONCLUSIONS
Elevated glucose concentrations inhibit the generation of extracellularly released reactive oxygen metabolites but have no effects on the intracellular respiratory burst in fMet-Leu-Phe-stimulated normal human neutrophils.
Oldenborg
P A
PA
Department of Integrative Medical Biology, Umeå University, Sweden. per-arne.oldenborg@histocel.umu.se
Sundqvist
I M
IM
Sehlin
J
J
D000328:Adult; D001786:Blood Glucose / Q000502:physiology; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D009195:Peroxidase / Q000097:blood; D016897:Respiratory Burst / Q000187:drug effects / Q000502:physiology*
D001786:Blood Glucose; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009195:Peroxidase; D005947:Glucose