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P2Y receptor activation enhances insulin release from pancreatic β-cells by triggering the cyclic AMP/protein kinase A pathway
- Source :
- Naunyn-Schmiedeberg's Archives of Pharmacology. 366:464-469
- Publication Year :
- 2002
- Publisher :
- Springer Science and Business Media LLC, 2002.
-
Abstract
- Adenine nucleotides stimulate insulin secretion by binding to P2 receptors of the pancreatic beta-cells; the stimulus-secretion coupling is not yet clearly established and may depend on the receptor subtype. The aim of the present study was to further investigate the mechanism whereby P2Y receptor agonists enhance glucose-induced insulin secretion. Experiments were performed in rat pancreatic islets and in the INS-1 secreting cell line in the presence of a slightly stimulating glucose concentration (8.3 mmol/l). In isolated islets, the P2Y receptor agonist ADPbetaS (50 micromol/l) induced a significant fivefold increase in the cyclic AMP (cAMP) content, from 43.4+/-3.7 fmol/10 islets in controls to 210.6+/-12.0; it still induced a 4.5-fold increase in cAMP content in the absence of calcium. In another series of experiments, ADPbetaS (50 micromol/l) significantly increased glucose-induced insulin secretion from 7.7+/-0.6 ng/3 islets in controls to 11.2+/-1.0. The adenylyl cyclase inhibitor SQ 22,536 (9-[tetrahydro-2-furanyl]-9 H-purin-6-amine; 100 micromol/l), which was ineffective alone, completely prevented the stimulating effect of ADPbetaS. In a set of experiments in which ADPbetaS increased glucose-induced insulin secretion from 10.0+/-0.7 ng/3 islets to 12.6+/-0.8, the inhibitor of cAMP-dependent protein kinase, TPCK (tos-phe-chloromethylketone; 3 micromol/l), which was ineffective alone, also prevented the stimulating effect of ADPbetaS. In incubated INS-1 cells, the P2Y receptor ligand ATPalphaS increased significantly both the content of cAMP and the release of insulin, in a concentration-dependent manner in the range of 50-150 micromol/l; the insulin release was significantly correlated with the cAMP content. In conclusion, the present results show that P2Y receptor agonists, ADPbetaS and ATPalphaS, amplify glucose-induced insulin secretion by activating beta-cell adenylyl cyclase and the subsequent cAMP/protein kinase A signaling pathway.
- Subjects :
- Male
Purinergic P2 Receptor Agonists
medicine.medical_specialty
Islets of Langerhans
Insulin receptor substrate
Internal medicine
Tumor Cells, Cultured
medicine
Animals
Insulin
Rats, Wistar
Protein kinase A signaling
Protein kinase A
Protein kinase B
Glucagon-like peptide 1 receptor
Pharmacology
Dose-Response Relationship, Drug
biology
Receptors, Purinergic P2
Chemistry
Pancreatic islets
General Medicine
Thionucleotides
Cyclic AMP-Dependent Protein Kinases
IRS2
Rats
Adenosine Diphosphate
Insulin receptor
Endocrinology
medicine.anatomical_structure
biology.protein
Subjects
Details
- ISSN :
- 14321912 and 00281298
- Volume :
- 366
- Database :
- OpenAIRE
- Journal :
- Naunyn-Schmiedeberg's Archives of Pharmacology
- Accession number :
- edsair.doi.dedup.....6f1b31bf192840a1de244975bb8711fd