Modulation of rat skeletal muscle chloride channels by activators and inhibitors of protein kinase C

✍ Scribed by D. Tricarico; D. Conte Camerino; S. Govoni; S. H. Bryant

• Book ID: 104787223
• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 451 KB
• Volume: 418
• Category: Article
• ISSN: 0031-6768
• DOI: 10.1007/bf00497778

✦ Synopsis

The membrane electrical parameters and component conductances of rat extensor digitorum longus muscle fibres were studied in vitro at 30 ~ with standard two microelectrode square pulse cable analysis in the presence of protein kinase C (PKC) activators and inhibitors. The PKC activator, 4-[3-phorbol-12,13 dibutyrate (4-13-PDB), (2-90 nM) blocked up to 67% chloride conductance (Gcl) in rat skeletal muscle fibres and induced myotonic hyperexcitability. The concentration necessary to produce a 50% block of the membrane Gcl was 23 nM. The "inactive" 4-a-phorbol-12,13 dibutyrate had no effect at 2 gM. The blocking effect of 4-13-PDB on Gcl was prevented by preincubation of the preparations with the PKC inhibitors, staurosporine (1-5 ~tM) and tetrahydropapaverolone (50-100 txM). The blocking effects on membrane Gcl of 4-13-PDB and its antagonism by the inhibitors used support the concept of the involvement of PKC in regulating C1 channels of mammalian skeletal muscle fibres.