Superoxide anion production and phagocytosis of crystals by cultured endothelial cells.
OBJECTIVE
To show that cultured human umbilical vein endothelial cells (HUVEC) are capable of phagocytizing inflammation-causing crystals and of generating superoxide anion (SOA) during phagocytosis.


METHODS
The superoxide dismutase-inhibitable reduction of nitroblue tetrazolium (NBT) dye was used as a measure of SOA production. Phagocytosis was quantified by light microscopy and confirmed by transmission electron microscopy. Cytochrome C was also studied but was found to undergo spontaneous reduction by monosodium urate (MSU) without cells.


RESULTS
Crystals of MSU, calcium oxalate, hydroxyapatite, and calcium pyrophosphate dihydrate (CPPD) were phagocytized and, except for the CPPD crystals, induced NBT reduction. Cholesterol and cholesterol monohydrate were neither phagocytized nor did they induce NBT reduction.


CONCLUSIONS
Endothelial cells may be a significant source of oxygen radicals in crystal-associated and other arthritides.
Department of Medicine, Cooper Hospital/University Medical Center, NJ 08103.
G F
GF
Falasca
A
A
Ramachandrula
K A
KA
Kelley
C R
CR
O'Connor
A J
AJ
Reginato
D002129:Calcium Oxalate / Q000276:immunology; D002131:Calcium Pyrophosphate / Q000276:immunology; D002784:Cholesterol / Q000276:immunology; D003460:Crystallization; D003571:Cytochalasin B / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000276:immunology; D006801:Humans; D006882:Hydroxyapatites / Q000276:immunology; D008854:Microscopy, Electron; D009580:Nitroblue Tetrazolium; D010084:Oxidation-Reduction; D010587:Phagocytosis / Q000187:drug effects / Q000502:physiology; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D014471:Umbilical Veins / Q000166:cytology; D014527:Uric Acid / Q000276:immunology / Q000378:metabolism
D003574:Cytochrome c Group; D006882:Hydroxyapatites; D013481:Superoxides; D002129:Calcium Oxalate; D014527:Uric Acid; D009580:Nitroblue Tetrazolium; D003571:Cytochalasin B; D002784:Cholesterol; D013482:Superoxide Dismutase; D002131:Calcium Pyrophosphate