INVOLVEMENT OF A2 ADENOSINE RECEPTORS IN SPINAL MECHANISMS OF ANTINOCICEPTION
INVOLVEMENT OF A2 ADENOSINE RECEPTORS IN SPINAL MECHANISMS OF ANTINOCICEPTION
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DOI：
10.1016/0014-2999(87)90254-8
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发表时间：
1987-07-09
影响因子：
5
通讯作者：
HOPKINS, CJ
中科院分区：
文献类型：
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作者：
DELANDER, GE;HOPKINS, CJ
初步研究表明，脊髓腺苷诱导显著的行为效应，并可能与脑室内吗啡刺激的下行抗痛觉系统相互作用。在本研究中，测定了鞘内注射腺苷激动剂（i.t）诱导的抗痛觉的等级效价。腺苷激动剂（i.t）与吗啡（i.c.v）诱导的抗避孕药的相互作用也被检查。通过摇尾和热板实验，观察到小鼠服用腺苷或腺苷激动剂后的剂量依赖性抗痛作用。效价顺序为：5' -N6-乙基羧氨基腺苷（NECA）、> N6（r -苯异丙基）-腺苷（R-PIA）、> 2-氯腺苷（CADO）、> N6-（s-苯异丙基）-腺苷（S-PIA）、>腺苷。腺苷激动剂（i.t）与吗啡（i.c.v）诱导的抗痛感协同作用的等级效价相同。此外，注射NECA或硝基苄基硫代肌苷（NBI），一种腺苷再摄取抑制剂，能够增强吗啡（i.c.v）诱导的抗痛感。高剂量腺苷激动剂（i.t）引起的后肢麻痹与抗感觉作用无关。在我们的研究中确定的等级效价支持A2腺苷受体参与脊髓抗痛觉机制。此外，这些结果证实脊髓腺苷与体外注射吗啡刺激的抗痛觉系统相互作用。
Preliminary investigations suggest that spinal adenosine induces significant behavioral effects and may interact with descending antinociceptive systems stimulated by morphine administered intracerebroventriculary (i.c.v.). in the present study, rank order potencies for antinociception induced by adenosine agonists administered intrathecally (i.t.) were determined. Interactions of adenosine agonisists (i.t.) with morphine (i.c.v.)-induced anticociception were also examined. Dose-dependent antinociception, as measured in tail flick and hot plate assays, was observed in mice administered adenosine or adenosine agonists i.t. Rank order potencies were 5''-N6-ethylcarboxamidoadenosine (NECA) > N6(R-phenylisopropyl)-adenosine (R-PIA) > 2-chloroadenosine (CADO) > N6-(s-phenylisopropyl)-adenosine (S-PIA) > adenosine. Rank order potencies were identical for adenosine agonist (i.t.) synergism with morphine (i.c.v.)-induced antinociception Further, i.t. injections of NECA or nitrobenzylthioinosine (NBI), an adenosine reuptake inhibitor, were able to potentiate morphine (i.c.v.)-induced antinociception. Hind limb paralysis induced by high doses of adenosine agonists (i.t.) was dissociated from antinociceptive effects. Rank order potencies determined in our studies support involvement of A2 adenosine receptors in spinal mechanisms of antinociception. In addition, these results confirm spinal adenosine interactions with antinociceptive systems stimulated by i.c.v. injections of morphine.