title: NMDA induces protein kinase C translocation in guinea pig cerebral synaptoneurosomes.
abstract: N-methyl-D-aspartate (NMDA)-induced translocation of protein kinase C from the cytosol to membrane fractions was examined by the [3H]phorbol 12,13-dibutyrate (PDBu) binding method in guinea pig cerebral synaptoneurosomes. Pretreatment of synaptoneurosomes with NMDA, but not that with quisqualate or kainate, induced changes in the distribution of [3H]PDBu binding in the cytosol and membrane fractions in a dose-dependent manner. The NMDA-induced changes of the binding were completely dependent on Ca2+ and inhibited by NMDA receptor antagonists Mg2+, 2-amino-5-phosphonovaleric acid and ketamine, but not by Zn2+. Glycine slightly potentiated the NMDA-induced changes of [3H]PDBu binding. NMDA stimulated Ca2+ uptake but not the phosphoinositide hydrolysis in the synaptoneurosomes. These results suggest that NMDA enhances Ca2+ influx through receptor-operated Ca2+ channels, increasing intracellular calcium concentration and thereby induces translocation of protein kinase C.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Osaka University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Etoh
authors.forename: A
authors.initials: A
authors.lastname: Baba
authors.forename: H
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D002118:Calcium / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D016202:N-Methylaspartate / Q000494:pharmacology*; D015240:Phorbol 12,13-Dibutyrate / Q000378:metabolism; D011493:Protein Kinase C / Q000032:analysis*; D013574:Synaptosomes / Q000187:drug effects* / Q000201:enzymology
chemical_list: D015240:Phorbol 12,13-Dibutyrate; D016202:N-Methylaspartate; D011493:Protein Kinase C; D002118:Calcium