title: all-trans-Retinal stimulates superoxide release and phospholipase C activity in neutrophils without significantly blocking protein kinase C.
abstract: all-trans-Retinal was previously shown to stimulate high levels of superoxide release by guinea pig neutrophils. When the cells, previously labeled with [3H]inositol, are treated with all-trans-retinal, they exhibit a decrease in the levels of [3H]inositol phospholipids and an increase in the accumulation of [3H]inositol phosphates. The maximal accumulation of inositol phosphates and the optimal rate of superoxide release occurred together at approximately 7 min after stimulation. The levels of [3H]inositol phosphates accumulated were comparable to those observed when the cells were stimulated with a chemotactic peptide. In direct measurements, using concentrations that stimulate intact cells maximally, all-trans-retinal was found not to inhibit protein kinase C from the cytosol of neutrophils significantly. This contrasts with the situation with this kinase obtained from other sources. These observations represent additional effects of vitamin A on cells.
mesh_terms: D005609:Free Radicals; D007295:Inositol Phosphates / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D011493:Protein Kinase C / Q000032:analysis*; D012172:Retinaldehyde / Q000494:pharmacology*; D012176:Retinoids / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010738:Type C Phospholipases / Q000032:analysis*
chemical_list: D005609:Free Radicals; D007295:Inositol Phosphates; D012176:Retinoids; D013481:Superoxides; D011493:Protein Kinase C; D010738:Type C Phospholipases; D013755:Tetradecanoylphorbol Acetate; D012172:Retinaldehyde