Influence of oxy-LDL and interleukin-8 on the platelet/PMNs adhesion and on chemotaxis-mediated induction of iNOS in neutrophils.
Selectin-P expression on platelets stimulated with thrombin was measured in terms of formation of "rosettes" according to Jungi et al. [9]. Selectin-P-mediated platelet/PMNs adhesion was inhibited by iloprost (IC50 = 5.0 nM), sodium nitroprusside (NaNP, IC50 = 0.93 microM) and interleukin-8 (IL-8, IC50 = 88 ng/ml), but activated dose-dependently by oxy-LDL (3-15 micrograms/ml). Glycogen-induced peritonitis in rats up-regulated the iNOS activity measured by the 2,3-[3H]-citrulline formation by the abdominal cavity PMNs up to 6 h after insult. Pretreatment with IL-8 (3 micrograms/300 g iv) decreased the amount of PMNs in ascites as well as its iNOS activity. Chemotaxis mediated iNOS gene expression of PMNs were measured by Northern blot hybridization. IL-8 (100 ng/ml) did not influence the PMNs iNOS gene expression induced by chemotaxis. We conclude that the decrease in iNOS activity by IL-8 involves postranslational modification of the enzyme activity.
Dembińska-Kieć
A
A
Department of Clinical Biochemistry, Medical College of Jagiellonian University, Kraków, Poland.
Dulak
J
J
Hartwich
J
J
Siedlecki
A
A
Polus
M
M
Krzesz
R
R
Partyka
L
L
Dudek
D
D
Brzezińska
A
A
Gruca
A
A
D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D002633:Chemotaxis / Q000187:drug effects*; D004790:Enzyme Induction / Q000187:drug effects; D006801:Humans; D016285:Iloprost / Q000494:pharmacology; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000494:pharmacology*; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D009504:Neutrophils / Q000201:enzymology*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000097:blood; D009599:Nitroprusside / Q000494:pharmacology; D019007:P-Selectin / Q000096:biosynthesis; D010538:Peritonitis / Q000139:chemically induced / Q000503:physiopathology; D010973:Platelet Adhesiveness / Q000187:drug effects*; D051381:Rats; D012397:Rosette Formation; D015854:Up-Regulation
D016209:Interleukin-8; D008077:Lipoproteins, LDL; D019007:P-Selectin; C099252:oxidized low density lipoprotein; D009599:Nitroprusside; D019001:Nitric Oxide Synthase; D016285:Iloprost