PKC-independent inhibition of glutamate exocytosis by arachidonic acid in rat cerebrocortical synaptosomes.
In rat cerebrocortical synaptosomes, the addition of 4 beta-phorbol dibutyrate (4 beta-PDBu) and arachidonic acid enhances and decreases, respectively, the glutamate release evoked by 4-aminopyridine. Pretreatment of synaptosomes with 12-O-tetradecanoylphorbol 13-acetate (TPA) or pre-incubation with staurosporine, prevent the stimulatory effect of 4 beta-PDBu, but are without effect on the inhibitory action of arachidonic acid. Moreover, methyl arachidonate, which is not effective as a PKC activator, also strongly inhibits glutamate exocytosis. These results suggest that PKC is not involved in the inhibition of glutamate release by arachidonic acid.
Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
I
I
Herrero
M T
MT
Miras-Portugal
J
J
Sánchez-Prieto
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000378:metabolism* / Q000648:ultrastructure; D004789:Enzyme Activation; D005089:Exocytosis; D005971:Glutamates / Q000378:metabolism*; D018698:Glutamic Acid; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D019311:Staurosporine; D013574:Synaptosomes / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000470:Alkaloids; D001095:Arachidonic Acids; D005971:Glutamates; D018698:Glutamic Acid; D011493:Protein Kinase C; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate