γ-L-谷氨酰-L-多巴的交感神经抑制作用并非通过激活清醒家兔的多巴胺2受体介导。
Sympatho-inhibitory effects of gamma-l-glutamyl-l-dopa are not mediated by activation of dopamine-2 receptors in conscious rabbits.
作者信息
Wang Z Q, Shimizu K, Way D, Secombe J, McGrath B P
机构信息
University Department of Medicine, Monash Medical Center, Melbourne, Victoria, Australia.
出版信息
Zhongguo Yao Li Xue Bao. 1995 May;16(3):193-7.
AIM
To define the role of dopamine-2 receptors in the sympatho-inhibitory effects of gamma-l-glutamyl-l-dopa in conscious rabbits.
METHOD
gamma-l-glutamyl-l-dopa (gludopa) was infused iv at 25 and 100 micrograms.kg-1.min-1 with and without prior dopamine-2 receptor blockade by YM-09151-2 (50 micrograms.kg-1 iv) in conscious rabbits.
RESULTS
Mean arterial pressure and heart rate remained unchanged while renal plasma flow increased. Arterial norepinephrine (NE) concentration, total and renal NE spillover rate were markedly decreased in a dose-related manner, which were not affected by prior dopamine-2 receptor blockade. Gludopa was detected in the whole brain (92 +/- 112 ng/g wet brain tissue) at the end of experiment although brain tissue levodopa, NE, and dopamine contents were not much different from those in the control group.
CONCLUSION
Gludopa decreased dose-dependently plasma NE concentration, and total and renal NE overflow to plasma, which were not mediated by activation of dopamine D2 receptors.
目的
确定多巴胺-2受体在γ-L-谷氨酰-L-多巴对清醒家兔交感神经抑制作用中的作用。
方法
在清醒家兔中，静脉注射γ-L-谷氨酰-L-多巴（谷氨酰多巴），剂量分别为25和100微克·千克-1·分钟-1，注射时预先给予或不给予YM-09151-2（50微克·千克-1静脉注射）阻断多巴胺-2受体。
结果
平均动脉压和心率保持不变，而肾血浆流量增加。动脉去甲肾上腺素（NE）浓度、总NE和肾NE溢出率均呈剂量依赖性显著降低，且不受预先多巴胺-2受体阻断的影响。实验结束时，在全脑中检测到谷氨酰多巴（92±112纳克/克湿脑组织），尽管脑组织左旋多巴、NE和多巴胺含量与对照组相比无明显差异。
结论
谷氨酰多巴剂量依赖性地降低血浆NE浓度以及总NE和肾NE向血浆中的溢出，这不是由多巴胺D2受体激活介导的。
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