Characterization of ionotropic glutamate receptor-mediated nitric oxide production in vivo in rats
Characterization of ionotropic glutamate receptor-mediated nitric oxide production in vivo in rats
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DOI：
10.1161/01.str.28.4.850
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发表时间：
1997-04-01
期刊：
影响因子：
8.3
通讯作者：
Koehler, RC
中科院分区：
文献类型：
--
作者：
Bhardwaj, A;Northington, FJ;Koehler, RC
背景与目的谷氨酸受体激活可刺激一氧化氮(NO)的产生，并可能在长时程增强和兴奋性毒性介导的损伤中发挥作用。我们研究了激动剂诱导激活离子通道连接的N-甲基-D-天冬氨酸(N-甲基-D-天冬氨酸)和alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic酸(AMPA)受体亚型对体内大鼠海马区NO产生的不同影响。我们还研究了丹曲林(Dantrolene)：一种先前被证明减弱代谢性谷氨酸受体对NO产生的刺激的丹曲林是否也减弱了离子谷氨酸受体对NO产生的刺激。方法将微透析探针放置在戊巴比妥钠麻醉的成年SD大鼠双侧海马CA3区，用含有3mU/L[C-14]L-精氨酸的人工脑脊液灌流5h。以出水中[C-14]L瓜氨酸的回收率作为NO产生的标志。在13组大鼠中，比较了不加任何药物的左右两侧探针对[C-14]-L-瓜氨酸回收率的影响，以及N-甲基-丙二醛、AMPA、WO合成酶抑制剂N-omega-硝基-L-精氨酸甲酯(NAME)、非竞争性谷氨酸受体阻滞剂MK-801、AMPA受体拮抗剂6-氰基-7-硝基-2，3-二酮(CNQX)和丹曲林的组合对[C-14]-L-瓜氨酸回收率的影响。对侧灌流1 mmol/L，L-NAME抑制[C-14]L-瓜氨酸的恢复。与单纯脑脊液灌流相比，灌流1 mmoL/L MK-801或1 mmoL/L CNQX可降低[C-14]L-瓜氨酸的恢复。灌流1 mmol/L NMDA可促进[C-14]L-瓜氨酸的恢复，L-NAME、MK-801和CNQX可减弱这种促进作用，但丹曲林不能减弱这一作用。1 mmol/L AMPA灌流可促进[C-14]L-瓜氨酸恢复。结论通过间接评估体内NO产生的方法，MK-801和CNQX的结果提示，NMDA型和AMPA受体的激活参与了大鼠海马区基础NO的产生。NMDA和AMPA激动剂增加NO的产生似乎涉及复杂的神经元相互作用，因为NMDA的作用被MK-SOI和CNQX减弱，因为AMPA的作用被CNQX和MK-801减弱。与代谢性谷氨酸受体激活相反，细胞内兰尼定钙通道的钙释放似乎不是离子亲性谷氨酸受体刺激NO产生的重要中介。
Background and Purpose Glutamate receptor activation can stimulate nitric oxide (NO) production and possibly play a role in long-term potentiation and excitotoxic-mediated injury. We studied the differential effect of agonist-induced activation of ion channel-linked N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor subtypes on NO production in vivo in rat hippocampus. We also studied whether dantrolene: a ryanodine calcium channel inhibitor previously shown to attenuate metabotropic glutamate receptor stimulation of NO production, also attenuated ionotropic glutamate receptor-mediated stimulation of NO production.Methods Microdialysis probes were placed bilaterally into the CA3 region of the hippocampus of pentobarbital-anesthetized adult Sprague-Dawley rats and were perfused for 5 hours with artificial cerebrospinal fluid (CSF) containing 3 mu mol/L [C-14]L-arginine. Recovery of [C-14]L-citrulline in the effluent was used as a marker of NO production. In 13 groups of rats, increases in [C-14]-L-citrulline recovery were compared between right- and left-sided probes perfused with no additional drugs versus combinations of NMDA, AMPA, the WO synthase inhibitor N-omega-nitro-L-arginine methyl ester (L-NAME), the noncompetitive glutamate receptor blocker MK-801, the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), and dantrolene.Results Recovery of [C-14]L-citrulline during pel fusion with artificial CSF progressively increased to 272 +/- 73 fmol/min (+/-SEM) over 5 hours. Contralateral perfusion with 1 mmol/L, L-NAME inhibited [[C-14]L-citrulline recovery. Perfusion with 1 mmol/L MK-801 or 1 mmol/L CNQX reduced [C-14]L-citrulline recovery compared with contralateral perfusion with CSF alone. Perfusion with 1 mmol/L NMDA enhanced [C-14]L-citrulline recovery, and this enhancement was attenuated by L-NAME, MK-801 and CNQX but not by dantrolene. Perfusion with 1 mmol/L AMPA enhanced [C-14]L-citrulline recovery. and this enhancement was also attenuated by L-NAME, MK-801, and CNQX but not by dantrolene.Conclusions Through an indirect method of assessing NO production in vivo, results with MK-801 and CNQX indicate that NMDA and AMPA receptor activation contribute to basal NO production in the rat hippocampus. Enhanced NO production with NMDA and AMPA agonists appears to involve a complex neuronal interaction because the effect of NMDA was attenuated by both MK-SOI and CNQX and because the effect of AMPA was attenuated by both CNQX and MK-801. In contrast to metabotropic glutamate receptor activation, release of calcium from intracellular ryanodine calcium channels does not appear to be a prominent mediator of ionotropic glutamate receptor stimulation of NO production.