The diacylglycerol kinase inhibitor R59022 potentiates superoxide production but not secretion induced by fMet-Leu-Phe: effects of leupeptin and the protein kinase C inhibitor H-7.
The addition of low concentrations of the chemotactic factor fMet-Leu-Phe to rabbit neutrophils in the absence of cytochalasin B produces very little superoxide. This level of superoxide can be greatly increased in neutrophils pretreated for 30 min with 10 microM of the diacyl-glycerol kinase inhibitor R59022. This potentiation occurs also in the presence of cytochalasin B. In addition, while the small level of superoxide generated by fMet-Leu-Phe is not inhibited by the protein kinase C inhibitor 1-(5-isoquinoline-sulfonyl)-2-methyl piperazine (H-7), the increase by R59022 is completely abolished by this compound. In addition, this increase can be potentiated further by leupeptin. Unlike superoxide generation, the release of lysozyme or N-acetyl-beta-glucosaminidase produced by fMet-Leu-Phe is not stimulated by R59022. The results presented here suggest that stimulation of the oxidative burst requires the generation and the maintenance of a sufficient amount of diacylglycerol and/or the rearrangement of the cytoskeleton such as the inhibition of actin polymerization. Furthermore, the membrane-associated form of protein kinase C is the one responsible for the activation of the oxidative burst. The relationship between protein kinase C activation and the stimulated oxidative burst and the physiological role of chemotactic factors in the functions of the neutrophils are discussed.
Gomez-Cambronero
J
J
Department of Physiology and Pathology, University of Connecticut Health Center, Farmington 06032.
Molski
T F
TF
Becker
E L
EL
Sha'afi
R I
RI
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D003571:Cytochalasin B / Q000494:pharmacology; D019852:Diacylglycerol Kinase; D007546:Isoquinolines / Q000494:pharmacology*; D007700:Kinetics; D007976:Leupeptins / Q000494:pharmacology*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology*; D010770:Phosphotransferases / Q000037:antagonists & inhibitors*; D010879:Piperazines / Q000494:pharmacology*; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D011744:Pyrimidinones / Q000494:pharmacology*; D011817:Rabbits; D013481:Superoxides / Q000097:blood*; D013844:Thiazoles / Q000494:pharmacology*
D007546:Isoquinolines; D007976:Leupeptins; D009842:Oligopeptides; D010879:Piperazines; D010972:Platelet Activating Factor; D011744:Pyrimidinones; D013844:Thiazoles; D013481:Superoxides; D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C047505:R 59022; D010770:Phosphotransferases; D019852:Diacylglycerol Kinase; D011493:Protein Kinase C; C032854:leupeptin