Fumio Suzuki

KYOWA HAKKO BIO Co., Ltd., Edo, Tōkyō, Japan

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Publications (2)7.95 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Adenosine A2a receptors have been localized to GABAergic striatopallidal neurons, but their functional role is unknown. To address this question, the modulation of endogenous GABA release by adenosine A2a receptors was examined in slices of rat globus pallidus. The selective adenosine A2a receptor agonist CGS-21680 (3.0-10 nM) significantly increased electrically stimulated release (overflow) of GABA, with 10 nM CGS-21680 resulting in a 44% increase compared with the control. Both the nonselective adenosine receptor antagonist 8-phenyltheophylline (10 microM) and the selective A2a receptor antagonist KF-17837 (100 nM) abolished the CGS-21680-induced increase in GABA overflow. Higher concentrations of CGS-21680 (0.10-1.0 microM) decreased GABA overflow by approximately 25%. 8-Phenyltheophylline (10 microM) antagonized these effects, whereas KF-17837 (100 nM) did not, suggesting actions of CGS-21680 on other adenosine receptors at these concentrations. These results demonstrate that activation of adenosine A2a receptors augments electrically stimulated release of GABA from globus pallidus slices and suggest a mechanism by which adenosine may modulate GABAergic output from the striatopallidal efferent system.
    Journal of Neurochemistry 07/1993; 60(6):2334-7. · 3.97 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: : Adenosine A2a receptors have been localized to GABAergic striatopallidal neurons, but their functional role is unknown. To address this question, the modulation of endogenous GABA release by adenosine A2a receptors was examined in slices of rat globus pallidus. The selective adenosine A2a receptor agonist CGS-21680 (3.0–10 nM) significantly increased electrically stimulated release (overflow) of GABA, with 10 nM CGS-21680 resulting in a 44% increase compared with the control. Both the nonselective adenosine receptor antagonist 8-phenyltheophylline (10 μM) and the selective A2a receptor antagonist KF-17837 (100 nM) abolished the CGS-21680-induced increase in GABA overflow. Higher concentrations of CGS-21680 (0.10–1.0 μM) decreased GABA overflow by ˜25%.8-Phenyltheophylline (10 μM) antagonized these effects, whereas KF-17837 (100 nM) did not, suggesting actions of CGS-21680 on other adenosine receptors at these concentrations. These results demonstrate that activation of adenosine A2a receptors augments electrically stimulated release of GABA from globus pallidus slices and suggest a mechanism by which adenosine may modulate GABAergic output from the striatopallidal efferent system.
    Journal of Neurochemistry 01/1993; 60(6):2334-2337. · 3.97 Impact Factor

Publication Stats

103 Citations
7.95 Total Impact Points

Institutions

  • 1993
    • KYOWA HAKKO BIO Co., Ltd.
      Edo, Tōkyō, Japan