Glutamate release upon purinergic action in the dorsal facial area of the medulla increases blood flow in the common carotid artery in cats
| Autor: | Jon-Son Kuo, Yu-Chuen Huang, Y.-W. Hung, Ching-Chang Cheng, Tony Jer-Fu Lee, Chi-Li Gong, Yung-Tsung Chiu, Nai-Nu Lin |
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| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Microinjections Purinergic Antagonists Carotid Artery Common Glutamic Acid Kainate receptor AMPA receptor Biology Receptors N-Methyl-D-Aspartate Purinergic Agonists chemistry.chemical_compound Adenosine Triphosphate Parasympathetic Nervous System Internal medicine medicine Animals PPADS Receptors AMPA Medulla Oblongata General Neuroscience Purinergic receptor Receptors Purinergic Adenosine receptor Endocrinology chemistry Regional Blood Flow Cats NMDA receptor Female |
| Zdroj: | Neuroscience. 163(3) |
| ISSN: | 1873-7544 |
| Popis: | Interactions of glutamatergic and purinergic actions in the medulla regulate important cardiovascular functions. The glutamatergic action in dorsal facial area (DFA) of the medulla increases blood flow of common carotid artery (CCA) in cats. We hypothesized that interactions of glutamatergic and purinergic actions in the DFA may regulate the CCA blood flow. Purinergic and glutamatergic agonists and antagonists were microinjected into the DFA through a four-barrel tubing in anesthetized cats. Drug effects were evaluated by changes in the CCA blood flow. Microinjection with 20 nmol ATP or alpha,beta-methyleneATP (alpha,beta-MeATP, a P2 purinergic receptor agonist) induced an increase of the CCA blood flow. This increase was dose-dependently reduced by prior administration with 1,3-dipropyl-8-p-sulfophenylxanthine (DPSPX, a specific P1 purinergic receptor antagonist), or pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS, a selective P2 purinergic receptor antagonist) as well as with MK-801 (a non-competitive NMDA receptor antagonist) or glutamate diethyl ester (GDEE, a competitive AMPA/kainate receptor antagonist). It was almost completely blocked by administrations with combined maximal doses of P1 and P2 receptor antagonists as well as NMDA and AMPA receptor antagonists. Nevertheless, P1 receptor agonist induced only mild and poorly reproducible increase in the CCA blood flow. In conclusion, prominent P2 and minor P1 purinergic receptors appear to be present in the DFA; the purinergic activation can mediate a release of glutamate that stimulates NMDA and AMPA to induce the increase of the CCA blood flows. These findings may provide important information for developing therapeutic strategy for diseases involving the CCA blood flow, such as hypertensive disease and cerebral ischemia. |
| Databáze: | OpenAIRE |
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