Abstract
Blepharismin is an endogenous photosensitizing pigment found in the protozoan Blepharisma. This pigment inhibited the generation of Superoxide anion (O2-) in neutrophils not only via a diacylglycerol-induced protein kinase C (PKC)-dependent reaction but also by an arachidonate-induced PKC-independent reaction. The inhibition was light and concentration dependent for both reactions. Light-activated inhibition was strong at wavelengths between 520 and 570nm but not above 610nm. PKC activity in neutrophils and from rat brain was inhibited by blepharismin in a light- and concentration dependent manner. Moreover, arachidonate-activated NADPH oxidase activity in a cell-free system was also inhibited by the pigment in a light- and concentration-dependent manner. These results suggest that blepharismin inhibits NADPH oxidase activation through the non-specific inhibition of various membrane-bound enzymes and that this inhibition may also be correlated with that of PKC.
Original language | English |
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Pages (from-to) | 529-536 |
Number of pages | 8 |
Journal | Biochemical Pharmacology |
Volume | 49 |
Issue number | 4 |
DOIs | |
Publication status | Published - Feb 14 1995 |
Externally published | Yes |
Keywords
- NADPH-oxida se
- active oxygen generation
- enzyme inhibition
- fluorescence of pigment
- perylenequinones
- tyrosine kinase
ASJC Scopus subject areas
- Biochemistry
- Pharmacology