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PROPIONIC ACID STIMULATES SUPEROXIDE GENERATION IN HUMAN NEUTROPHILS
Author(s) -
NAKAO SUMI,
MORIYA YOSHIKO,
FURUYAMA SHUNSUKE,
NIEDERMAN RICHARD,
SUGIYA HIROSHI
Publication year - 1998
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1006/cbir.1998.0263
Subject(s) - thapsigargin , superoxide , chemistry , biochemistry , extracellular , intracellular , enzyme
Short‐chain carboxylic acids are the metabolic by‐products of pathogenic anaerobic bacteria and are found at sites of infection in millimolar quantities. We previously reported that propionic acid, one of the short‐chain carboxylic acids, induces an increase in intracellular Ca 2+ ([Ca 2+ ] i ) in human neutrophils. Here we investigate the effect of propionic acid on superoxide generation in human neutrophils. Propionic acid (10m m ) induced inositol 1,4,5‐trisphosphate (IP 3 ) formation and a rapidly transient increase in [Ca 2+ ] i , but not superoxide generation, whereas 1μ m formylmethionyl‐leucyl‐phenylalanine (fMLP), a widely used neutrophil‐stimulating bacterial peptide, stimulated not only IP 3 formation and Ca 2+ mobilization but also superoxide generation. The IP 3 level induced by propionic acid was slightly lower than that induced by fMLP. The transient increase in [Ca 2+ ] i induced by propionic acid immediately returned to the basal level, whereas a sustained increase in [Ca 2+ ] i , which was higher than the basal level, following a transient increase in [Ca 2+ ] i was induced by fMLP. The peak level induced by propionic acid was lower than that with fMLP. In the absence of extracellular Ca 2+ , thapsigargin, a potent inhibitor of endoplasmic reticulum Ca 2+ ‐ATPase, induced an increase in [Ca 2+ ] i even after propionic acid stimulation, but not after fMLP. The Ca 2+ ionophore A23187 and thapsigargin induced superoxide generation by themselves. Propionic acid enhanced the superoxide generating effect of A23187 and thapsigargin. These results suggest that Ca 2+ mobilization induced by propionic acid is much weaker than that with fMLP, and propionic acid is able to generate superoxide in the presence of a Ca 2+ ionophore and a Ca 2+ influx activator.