Xu Z, Johnson A K
Departments of Psychology and Pharmacology, and The Cardiovascular Center, 11 Seashore Hall E, University of Iowa, Iowa City, IA 52242-1407, USA.
Brain Res. 1998 Oct 12;808(1):124-7. doi: 10.1016/s0006-8993(98)00761-6.
Glutamate has been implicated in the central control of mechanisms that maintain body fluid homeostasis. The present studies demonstrate that intracerebroventricular (i.c.v.) injections of the non-N-methyl-d-aspartate (NMDA) receptor antagonists 6, 7-dinitroquinoxaline-2,3-dione (DNQX) and 6-cyano-7-nitroquinoxaline-2,3 dione (CNQX) induce drinking in rats. The dipsogenic effect of i.c.v. DNQX was antagonized by the non-NMDA receptor agonist alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA). The water intake induced by DNQX was also blocked by pretreatment with a NMDA receptor antagonist, MK-801, but not by angiotensin type 1 (AT1) or acetylcholine muscarinic receptor antagonists (losartan and atropine). The results indicate that non-NMDA receptors may exert a tonic inhibitory effect within brain circuits that control dipsogenic activity and that functional integrity of NMDA receptors may be required for the non-NMDA receptor antagonists to induce water intake.
谷氨酸已被认为参与维持体液平衡机制的中枢控制。目前的研究表明，脑室内注射非N-甲基-D-天冬氨酸（NMDA）受体拮抗剂6,7-二硝基喹喔啉-2,3-二酮（DNQX）和6-氰基-7-硝基喹喔啉-2,3-二酮（CNQX）可诱导大鼠饮水。脑室内注射DNQX的致渴作用可被非NMDA受体激动剂α-氨基-3-羟基-5-甲基异恶唑-4-丙酸（AMPA）拮抗。DNQX诱导的饮水量也可被NMDA受体拮抗剂MK-801预处理所阻断，但不能被1型血管紧张素（AT1）或乙酰胆碱毒蕈碱受体拮抗剂（氯沙坦和阿托品）阻断。结果表明，非NMDA受体可能在控制致渴活动的脑回路中发挥紧张性抑制作用，并且非NMDA受体拮抗剂诱导饮水可能需要NMDA受体的功能完整性。
