Eison A S, Wright R N, Freeman R
CNS Special Projects, Bristol-Myers Squibb Company, Wallingford, Connecticut 06492.
Life Sci. 1992;51(10):PL95-9. doi: 10.1016/0024-3205(92)90491-7.
Treatment of rats with 5-carboxamidotryptamine (5-CT) or 5-methoxy-tryptamine (5-MeOT) induces a hindlimb scratch response. These compounds have high affinity for 5-HT1A and 5-HT1D receptors. The selective 5-HT1A receptor agonist N,N-dipropyl-5-CT (DP-5-CT) also induced hindlimb scratching while the selective 5-HT1D receptor agonist, sumatriptan, did not. 5-CT-induced hindlimb scratching was inhibited dose-dependently by several 5-HT1A antagonists (BMY 7378, NAN-190, MDL 73005EF and pindobind-5-HT1A) as well as the non-selective 5-HT antagonist, methiothepin. Pretreatment of rats with the serotonin (5-HT) synthesis inhibitor, p-chlorophenylalanine (PCPA) or the 5-HT depleting agent, reserpine, markedly attenuated 5-CT-induced hindlimb scratching. These data suggest that hindlimb scratching induced by 5-HT agonists may not be centrally mediated but rather may be mediated by a neuronal 5-HT1A receptor localized outside the blood-brain barrier.
用5-羧基酰胺色胺（5-CT）或5-甲氧基色胺（5-MeOT）处理大鼠会诱发后肢搔抓反应。这些化合物对5-HT1A和5-HT1D受体具有高亲和力。选择性5-HT1A受体激动剂N，N-二丙基-5-CT（DP-5-CT）也诱发后肢搔抓，而选择性5-HT1D受体激动剂舒马曲坦则不会。几种5-HT1A拮抗剂（BMY 7378、NAN-190、MDL 73005EF和pindobind-5-HT1A）以及非选择性5-HT拮抗剂美索达嗪均能剂量依赖性地抑制5-CT诱发的后肢搔抓。用血清素（5-HT）合成抑制剂对氯苯丙氨酸（PCPA）或5-HT耗竭剂利血平预处理大鼠，可显著减弱5-CT诱发的后肢搔抓。这些数据表明，5-HT激动剂诱发的后肢搔抓可能不是由中枢介导的，而是可能由位于血脑屏障外的神经元5-HT1A受体介导的。
