S. Matsumoto, S. Yoshida, M. Ikeda, C. Saiki, M. Takeda
{"title":"Effects of PKC and PKA Inhibitors on the cAMP-Stimulant-Induced Enhancement of Tetrodotoxin-Resistant Na + (Nav1.8) Currents","authors":"S. Matsumoto, S. Yoshida, M. Ikeda, C. Saiki, M. Takeda","doi":"10.2174/1874143600802010017","DOIUrl":null,"url":null,"abstract":"The protein kinase C (PKC) inhibitor bisindolymaleimide Ro-31-8425 (Ro-31-8425) decreases the peak tetro- dotoxin-resistant (TTX-R) Na + (Nav1.8) current in nodose ganglion (NG) neurons, and this decrease is not altered by si- multaneous application of 8-bromo-cAMP (8-Br-cAMP), phorbol 12-myristate 13-acetate (PMA, a PKC activator) or forskolin (a cAMP analogue). Intracellular application of the endogenous protein kinase A (PKA) inhibitor, protein kinase inhibitor (PKI) abolishes the increase in the peak Nav1.8 current that occurs in response to the applications of 8-Br- cAMP, PMA, forskolin, or prostaglandin E2 (PGE2, an adenyl cyclase activator). At a higher concentration (0.5 mM) compared with a sufficient concentration (0.01 mM) to block the cAMP-stimulant Nav1.8 current, PKI still attenuated the Ro-31-8425-induced decrease in peak Nav1.8 current. When we considered these results together, cAMP-stimulant- induced modification of Nav1.8 currents is mediated by the activation of both PKA and PKC, and PKC may be located upstream of PKA.","PeriodicalId":22907,"journal":{"name":"The Open Pharmacology Journal","volume":"120 1","pages":"17-19"},"PeriodicalIF":0.0000,"publicationDate":"2008-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Open Pharmacology Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2174/1874143600802010017","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
The protein kinase C (PKC) inhibitor bisindolymaleimide Ro-31-8425 (Ro-31-8425) decreases the peak tetro- dotoxin-resistant (TTX-R) Na + (Nav1.8) current in nodose ganglion (NG) neurons, and this decrease is not altered by si- multaneous application of 8-bromo-cAMP (8-Br-cAMP), phorbol 12-myristate 13-acetate (PMA, a PKC activator) or forskolin (a cAMP analogue). Intracellular application of the endogenous protein kinase A (PKA) inhibitor, protein kinase inhibitor (PKI) abolishes the increase in the peak Nav1.8 current that occurs in response to the applications of 8-Br- cAMP, PMA, forskolin, or prostaglandin E2 (PGE2, an adenyl cyclase activator). At a higher concentration (0.5 mM) compared with a sufficient concentration (0.01 mM) to block the cAMP-stimulant Nav1.8 current, PKI still attenuated the Ro-31-8425-induced decrease in peak Nav1.8 current. When we considered these results together, cAMP-stimulant- induced modification of Nav1.8 currents is mediated by the activation of both PKA and PKC, and PKC may be located upstream of PKA.