J Korean Neurosurg Soc.
1995 Feb;24(2):115-122.
A Study on the Role of Protein Kinase C upon the Acetylcholine Release in the Rat Hippocampus
- Affiliations
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- 1Department of Neurosurgery, Wonkwang University, School of Medicine, Iri, Korea.
- 2Department of Pharmacology, Wonkwang University, School of Medicine, Iri, Korea.
Abstract
- The effects and interactions of 4 beta-phorbol 12,13-dibutyrate(PDB) and polymyxin B(PMB) with adenosine on the electrically-evoked acetylcholine(ACh) release were studied in rat hippocampus. Slices from rat hippocampus were equilibrated with 3H-choline and the release of the labeled product, 3H-ACh, which was evoked by electrical stimulation(3Hz, 2ms, 5Vcm-1, rectangular pulses) was measured. PDB(0.3-10 micorM), a selective protein kinase C(PKC) activator, increased the evoked ACh release in a dose related fashion with an increase in the basal rate of release. The effects of 1(M PDB were significantly inhibited by 0.3 micorM tetrodotoxin(TTX) pretreatment or Ca++-free medium. PMB(0.03-1mg), a selective PKC inhibitor, decreased the ACh release in a dose dependent manner with an increase in the basal rate of release. Adenosine(1-10 micorM) decreased the ACh release without changing the basal rate or release, and this effect was significantly inhibited by 8-cyclopentyl-1,3-dipropylxanthine(2 micorM), a selective A1-receptor antagonist treatment. However, adenosine effects were not affected by PDB and PMB. These results indicate that the PKC play a role in the ACh release in the rat hippocampus but is not involved in the post-receptor mechanism of the A1-adenosine receptor.