Inhibition of superoxide generation and of increase in intracellular Ca2+ concentration by zinc in rat neutrophils stimulated with zymosan.
The effect of Zn2+ on the O2- generation and change in intracellular Ca2+ concentration ([Ca2+]i) of rat peritoneal neutrophils was studied. Zymosan (serum-treated zymosan (STZ))-induced O2- generation was inhibited by Zn2+ at concentrations as low as 10 microM. A large amount of the inhibition was observed in the absence of extracellular Ca2+ but the inhibition could not be restored by increasing the extracellular Ca2+ concentration, indicating that Zn2+ does not necessarily inhibit the O2- generation competitively with extracellular Ca2+. In the absence of extracellular Ca2+, Zn2+ inhibited STZ-induced transient increase in [Ca2+]i in the concentration range that evoked a marked inhibition in the O2- generation. On the other hand, Zn2+ did not inhibit significantly STZ-induced uptake of 45Ca2+ from extracellular medium by the cells. From these results, it is suggested that Zn2+ inhibits STZ-induced release of Ca2+ from intracellular storage sites, resulting in the suppression of the activation mechanism of neutrophils.
Yatsuyanagi
J
J
Hokkaido Institute of Pharmaceutical Sciences, Otaru, Japan.
Muraoka
S
S
Tsutsui
R
R
Ogiso
T
T
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013481:Superoxides / Q000378:metabolism*; D015032:Zinc / Q000494:pharmacology*; D015054:Zymosan / Q000494:pharmacology*
D013481:Superoxides; D015054:Zymosan; D007770:L-Lactate Dehydrogenase; D015032:Zinc; D002118:Calcium