Maura G, Marcoli M, Pepicelli O, Rosu C, Viola C, Raiteri M
Dipartimento di Medicina Sperimentale, Sezione di Farmacologia e Tossicologia, Università di Genova, Viale Cembrano 4, 16148 Genova, Italy.
Br J Pharmacol. 2000 Aug;130(8):1853-8. doi: 10.1038/sj.bjp.0703510.
The NMDA receptor/nitric oxide (NO)/cyclic GMP pathway and its modulation by 5-hydroxytryptamine (5-HT) was studied in slices of neocortical samples obtained from patients undergoing neurosurgery. The cyclic GMP elevation produced by 100 microM NMDA was blocked by 100 microM of the NO synthase inhibitor N(G)-nitro-L-arginine (L-NOARG) or by 10 microM of the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3,-alpha] quinoxaline-1-one (ODQ). The NMDA effect was prevented by 5-HT or by the 5-HT(2) agonist (+/-)-1-(2, 5-dimethoxy-4-iodophenyl)-2-aminopropane ((+/-)-DOI; EC(50)=22 nM). The (+/-)-DOI inhibition was insensitive to the 5-HT(2A) receptor antagonist MDL 100907 or the 5-HT(2B) antagonist rauwolscine; it was largely prevented by 1 microM of the non-selective 5-HT(2C) antagonists mesulergine (5-HT(2A,B,C)), ketanserin (5-HT(2A,C)) or SB 200646A (5-HT(2B,C)); it was completely abolished by 0.1 microM of the selective 5-HT(2C) receptor antagonist SB 242084. The NMDA-induced cyclic GMP elevation also was potently inhibited by the selective 5-HT(2C) agonist RO 60-0175 and by the antidepressant trazodone, both added at 1 microM, in an SB 242084-sensitive manner. Finally, the 5-HT(1A) agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT; 1 microM) inhibited the NMDA-evoked cyclic GMP response, an effect blocked by the selective 5-HT(1A) receptor antagonist WAY 100635. In conclusion, the NMDA receptor/NO/cyclic GMP pathway in human neocortex slices can be potently inhibited by activation of 5-HT(2C) or 5-HT(1A) receptors.
在接受神经外科手术患者的新皮质样本切片中,研究了N-甲基-D-天冬氨酸(NMDA)受体/一氧化氮(NO)/环磷酸鸟苷(cGMP)通路及其受5-羟色胺(5-HT)的调节情况。100微摩尔的NMDA所引起的cGMP升高,被100微摩尔的NO合酶抑制剂N(G)-硝基-L-精氨酸(L-NOARG)或10微摩尔的可溶性鸟苷酸环化酶抑制剂1H-[1,2,4]恶二唑并[4,3,-α]喹喔啉-1-酮(ODQ)所阻断。5-HT或5-HT(2)激动剂(±)-1-(2,5-二甲氧基-4-碘苯基)-2-氨基丙烷((±)-DOI;半数有效浓度(EC50)=22纳摩尔)可阻止NMDA的作用。(±)-DOI的抑制作用对5-HT(2A)受体拮抗剂MDL 100907或5-HT(2B)拮抗剂萝芙素不敏感;它在很大程度上被1微摩尔的非选择性5-HT(2C)拮抗剂美舒麦角(5-HT(2A、B、C))、酮色林(5-HT(2A、C))或SB 200646A(5-HT(2B、C))所阻止;它被0.1微摩尔的选择性5-HT(2C)受体拮抗剂SB 242084完全消除。NMDA诱导的cGMP升高也被选择性5-HT(2C)激动剂RO 60-0175和抗抑郁药曲唑酮以SB 242084敏感的方式有效抑制,二者均以1微摩尔的浓度添加。最后,5-HT(1A)激动剂8-羟基-2-(二正丙基氨基)四氢萘(8-OH-DPAT;1微摩尔)抑制了NMDA诱发的cGMP反应,该作用被选择性5-HT(1A)受体拮抗剂WAY 100635阻断。总之,人新皮质切片中的NMDA受体/NO/cGMP通路可被5-HT(2C)或5-HT(1A)受体的激活有效抑制。