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多巴胺D_(1)受体参与新生鼠离体延髓脑片呼吸节律性放电的调节

焦勇钢, 吴中海

南方医科大学生理学教研室.广东,广州 510515

摘要

该研究旨在探讨多巴胺D_(1)受体在延髓离体脑片基本节律性呼吸放电调节中的作用。以改良的Kreb's液(modified Kreb's perfusion,MKS)恒温灌流Sprague--Dawley大鼠(0---3d)离体延髓脑片标本,稳定记录到与之相连的舌下神经根的呼吸节律性放电活动(respiratory rhythmical discharge activity,RRDA)后,第一组({sl n}=5)先给予多巴胺D_(1)受体特异性激动剂[{sl cis}--(±)--1--(Aminomethyl)--3,4--dihydro--3--phenyl--1H--2--Benzopyran--5,6--Diolhy--drochlo--ride,A68930]灌流10min,用MKS洗脱后,再给予多巴胺D_(1)受体特异性拮抗剂[R(+)--7--Chloro--8--hydroxy--3--methyl--1--phenyl--2,3,4,5--tetrahydro--1H--3--benzazepine hydrochloride,SCH--23390]灌流10min;第二组({sl n}=5)先给予A68930持续灌流10min后再给予A68930+SCH--23390持续灌流10min;观察各时间点舌下神经根RRDA的变化。结果显示,给予A68930灌流后呼吸周期(respiratory cycle,RC)和呼气时程(expiratory time,TE)显著缩短,放电积分幅度(integral amplitude,IA)增加,吸气时程(inspiratory time,TI)无明显变化;给予SCH--23390后RC、TE显著延长、TI显著缩短、IA减小,而且A68930的作用可以被SCH--23390部分逆转。这些观察结果提示多巴胺D_(1)受体参与了哺乳动物基本呼吸频率和幅度的调节。

关键词： 多巴胺D_(1)受体; 延髓; 呼吸节律

D_(1)--dopamine receptor is involved in the modulation of the respiratory rhythmical discharge

Jiao Yonggang, Wu Zhonghai

Department of Physiology,Southern Medical University.Guangzhou 510515,Guangdong

Abstract

To explore the role of D_(1)-dopamine receptor in the modulation of basic respiratory rhythm,neonatal(0-3 d) Sprague-Dawley rats of either sex were used.The medulla oblongata slice was prepared and the surgical procedure was performed in the modified Kreb's solution(MKS) with continuous ventilating 95% O_(2) and 5% CO_(2) and ended in 3 min.A 600-700 #mu#m single transverse slice containing the hypoglossal nerve roots and some parts of the ventral respiratory group was cut.The preparation was quickly transferred to a recording chamber and continuously perfused with oxygen-saturated MKS at a rate of 4-6 mL/min at 27-29℃.Ten medulla oblongata slice preparations were randomly divided into two groups.In group I,the preparations were perfused with perfusion solution containing D_(1)-dopamine receptor specific agonist cis-(±)-1-(Aminomethyl)-3,4-dihydro-3-phenyl-1H-2-Benzopyran-5,6-Diolhy-drochlo-ride(A68930,5 #mu#mol/L) for 10 min first;after washing out,the preparations were then perfused with perfusion solution containing D_(1)-dopamine receptor specific antagonist R(+)-7-Chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride(SCH-23390,2 #mu#mol/L) for 10 min.In group Ⅱ,after perfusion with A68930 for 10 min,the preparations were perfused with additional A68930 + SCH-23390 for 10 min.Respiratory rhythmical discharge activity(RRDA) of the rootlets of hypoglossal nerve was recorded by suction electrodes.The results showed that A68930 shortened the respiratory cycle(RC) and expiratory time(TE) with an increase in the integral amplitude(IA).However,SCH-23390 significantly prolonged RC and TE,and decreased IA with a decrease in inspiratory time(TI).Moreover,the effect of A68930 on the respiratory rhythm was partially reversed by additional application of A68930 + SCH-23390.These results indicate that D_(1)-dopamine receptor is possibly involved in the modulation of the RRDA in the isolated neonatal rat brainstem slice.

Key words: D_(1)-dopamine receptor;medulla oblongata;Respiratory rhythm

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引用本文：

焦勇钢, 吴中海. 多巴胺D_(1)受体参与新生鼠离体延髓脑片呼吸节律性放电的调节[J]. 生理学报 2008; 60 (6): 704-708.

Jiao Yonggang, Wu Zhonghai. D_(1)--dopamine receptor is involved in the modulation of the respiratory rhythmical discharge. Acta Physiol Sin 2008; 60 (6): 704-708 (in Chinese with English abstract).