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Extracellular ATP-induced calcium channel inhibition mediated by P1/P2Y purinoceptors in hamster submandibular ganglion neurons.
- Source :
-
British journal of pharmacology [Br J Pharmacol] 2003 Apr; Vol. 138 (8), pp. 1535-43. - Publication Year :
- 2003
-
Abstract
- 1. The presence and profile of purinoceptors in neurons of the hamster submandibular ganglion (SMG) have been studied using the whole-cell configuration of the patch-clamp technique. 2. Extracellular application of adenosine 5'-triphosphate (ATP) reversibly inhibited voltage-dependent Ca(2+) channel (VDCC) currents (I(Ca)) via G(i/o)-protein in a voltage-dependent manner. 3. Extracellular application of uridine 5'-triphosphate (UTP), 2-methylthioATP (2-MeSATP), alpha,beta-methylene ATP (alpha,beta-MeATP) and adenosine 5'-diphosphate (ADP) also inhibited I(Ca). The rank order of potency was ATP=UTP>ADP>2-MeSATP=alpha,beta-MeATP. 4. The P2 purinoceptor antagonists, suramin and pyridoxal-5-phosphate-6-azophenyl-2', 4'-disulfonic acid (PPADS), partially antagonized the ATP-induced inhibition of I(Ca), while coapplication of suramin and the P1 purinoceptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), virtually abolished I(Ca) inhibition. DPCPX alone partially antagonized I(Ca) inhibition. 5. Suramin antagonized the UTP-induced inhibition of I(Ca), while DPCPX had no effect. 6. Extracellular application of adenosine (ADO) also inhibited I(Ca) in a voltage-dependent manner via G(i/o)-protein activation. 7. Mainly N- and P/Q-type VDCCs were inhibited by both ATP and ADO via G(i/o)-protein betagamma subunits in seemingly convergence pathways.
- Subjects :
- Adenosine Triphosphate pharmacology
Animals
Cricetinae
Dose-Response Relationship, Drug
Extracellular Fluid drug effects
Extracellular Fluid metabolism
Ganglia, Parasympathetic drug effects
Male
Neurons drug effects
Neurons metabolism
Submandibular Gland drug effects
Submandibular Gland metabolism
Adenosine Triphosphate metabolism
Calcium Channels metabolism
Ganglia, Parasympathetic metabolism
Receptors, Purinergic P1 metabolism
Receptors, Purinergic P2 metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0007-1188
- Volume :
- 138
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- British journal of pharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 12721109
- Full Text :
- https://doi.org/10.1038/sj.bjp.0705174