Endogenous adenosine facilitates neurotransmission via A2A adenosine receptors in the rat superior colliculus in vivo
| Autor: | Shozo Ishikawa, Kiyofumi Saijoh, Yasuhiro Okada |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Superior Colliculi
medicine.medical_specialty Adenosine Purinergic Antagonists Adenosine receptor antagonist Synaptic Transmission Adenosine A1 receptor Internal medicine medicine Animals RNA Messenger Enzyme Inhibitors Molecular Biology Chemistry Adenine General Neuroscience Receptors Purinergic P1 Purinergic signalling Adenosine A3 receptor Adenosine receptor Rats Electrophysiology Endocrinology Purines Xanthines Neurology (clinical) Adenosine Deaminase Inhibitor Adenosine A2B receptor Developmental Biology medicine.drug |
| Zdroj: | Brain Research. 757:268-275 |
| ISSN: | 0006-8993 |
| DOI: | 10.1016/s0006-8993(96)01436-9 |
| Popis: | The concentration of endogenous adenosine in the cerebrospinal fluid increased 2–3-fold of the original level in the area of rat superior colliculus after the intraperitoneal administration of an adenosine deaminase inhibitor, EHNA (erythro-9-(2-hydroxy-3-nonyl)adenosine, 10 mg/kg). Potentials evoked in the superior colliculus by optic tract stimulation were also facilitated by 120–160% of their initial amplitudes. A selective A1 adenosine receptor antagonist, DPCPX (8-cyclopentyl-1,3-dipropylxanthine), failed to reduce such EHNA-induced facilitation. However, a selective A2A adenosine receptor antagonist, KF17837 (8(3,4-dimethoxystyryl)-1,3-dipropyl-7-methylxanthine) completely eliminated the facilitatory effects of EHNA. Northern blot analysis demonstrated abundant expression of A1 adenosine receptor mRNA in the superior colliculus. RT-PCR analysis was able to detect the concomitant expression of A2A adenosine receptor mRNA, but at levels lower than one-tenth of the striatal expression. In the superior colliculus, A2A adenosine receptors function predominantly on the facilitatory effects of adenosine, irrespective of the ubiquitous expression of A1 adenosine receptors. |
| Databáze: | OpenAIRE |
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