TPA and resiniferatoxin-mediated activation of NADPH-oxidase. A possible role for Rx-kinase augmentation of PKC.
The non-tumour promoting irritant, resiniferatoxin, was capable of activating the NADPH-oxidase respiratory burst of starch-elicited, but not resident mouse peritoneal macrophages in vitro. Unlike TPA, the response was synergised by incubation with zymosan. The Rx-stimulated NADPH-oxidase activity in a cell-free assay was selectively enhanced in the presence of exogenous Rx-kinase rather than PKC and in the absence of Ca2+. Since resiniferatoxin is a poor activator of PKC, it is probable that the Ca2(+)-independent Rx-kinase plays a role in activation of the macrophage respiratory burst following stimulation by zymosan.
Evans
A T
AT
Department of Pharmacognosy, School of Pharmacy, London, UK.
Sharma
P
P
Ryves
W J
WJ
Evans
F J
FJ
D000818:Animals; D002478:Cells, Cultured; D004224:Diterpenes / Q000494:pharmacology*; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology; D008297:Male; D051379:Mice; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D019255:NADPH Oxidases; D010084:Oxidation-Reduction; D011493:Protein Kinase C / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D015054:Zymosan / Q000494:pharmacology
D004224:Diterpenes; D015054:Zymosan; C024353:resiniferatoxin; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate