多巴胺对兔颈上神经节的作用。

Effects of dopamine on the superior cervical ganglion of the rabbit.

作者信息

Dun N, Nishi S

出版信息

J Physiol. 1974 May;239(1):155-64. doi: 10.1113/jphysiol.1974.sp010560.

DOI:10.1113/jphysiol.1974.sp010560

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1330942/

Abstract

The effects of dopamine on isolated rabbit superior cervical ganglion were investigated with intracellular recording techniques.2. Dopamine (10(-5)-10(-3)M) depressed the amplitude of the excitatory post-synaptic potential (e.p.s.p.) and blocked impulse transmission.3. Dopamine (10(-4)M) induced a slight (2-5 mV) post-synaptic hyperpolarization without altering membrane conductance.4. The post-synaptic membrane sensitivity to acetylcholine (ACh) applied iontophoretically was not affected by dopamine.5. Dopamine decreased the frequency of miniature excitatory post-synaptic potentials (m.e.p.s.p.s) in a high K(+) solution, with no change in the amplitude of m.e.p.s.p.s.6. Dopamine reduced the quantal content of the e.p.s.p. in a low Ca(2+) and high Mg(2+) solution, but had no effect on the quantal size.7. The ganglionic blocking effect of dopamine was antagonized by phenoxybenzamine, but not by propranolol.8. The results show that the ganglionic depressant effect of dopamine is exerted primarily through an alpha-adrenoceptive site at the presynaptic nerve terminal.

摘要

采用细胞内记录技术研究了多巴胺对离体兔颈上神经节的作用。
多巴胺（10⁻⁵ - 10⁻³M）降低兴奋性突触后电位（e.p.s.p.）的幅度并阻断冲动传递。
多巴胺（10⁻⁴M）引起轻微（2 - 5 mV）的突触后超极化，而不改变膜电导。
离子电泳施加乙酰胆碱（ACh）时，突触后膜对其的敏感性不受多巴胺影响。
在高钾溶液中，多巴胺降低微小兴奋性突触后电位（m.e.p.s.p.s）的频率，而m.e.p.s.p.s的幅度无变化。
在低钙高镁溶液中，多巴胺降低e.p.s.p.的量子含量，但对量子大小无影响。
多巴胺的神经节阻断作用可被酚苄明拮抗，但不能被普萘洛尔拮抗。
结果表明，多巴胺的神经节抑制作用主要通过突触前神经末梢的α - 肾上腺素能受体部位发挥。