Responses to dopamine of isolated human gastroepiploic arteries.
Responses to dopamine of isolated human gastroepiploic arteries.
复制标题
离体人胃网膜动脉对多巴胺的反应。
DOI：
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发表时间：
1989
影响因子：
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通讯作者：
T. Okamura
中科院分区：
文献类型：
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作者：
N. Toda;H. Okunishi;T. Okamura
我们比较了人胃网膜动脉（近端部分）及其网膜分支（远端部分）的螺旋条对多巴胺的反应，这些动脉部分被前列腺素F2 α收缩。多巴胺在近端动脉中产生剂量相关的收缩，用酚妥拉明治疗后，收缩被逆转为松弛。另一方面，远端动脉对低浓度多巴胺有松弛反应，对高浓度多巴胺有收缩反应。舒张反应被氟哌啶醇选择性抑制，并被SCH23390逆转为收缩，但多潘立酮和心得安不受影响。胺诱导的松弛不因内皮的去除而减少。远端动脉，多巴胺引起松弛，对去甲肾上腺素有剂量相关的收缩反应，这被酚妥拉明抑制，但不会逆转为松弛。可以得出结论，多巴胺收缩人胃网膜近端动脉，主要是由于α -肾上腺素受体的激活，并通过优先作用于多巴胺能da1受体而扩张远端动脉，可能存在于平滑肌中。在远端动脉中，去甲肾上腺素激活α -肾上腺素受体的能力明显高于多巴胺。
Responses to dopamine were compared in helical strips of human gastroepiploic arteries (proximal portion) and their epiploic branches (distal portion), partially contracted with prostaglandin F2 alpha. Dopamine produced a dose-related contraction in the proximal arteries, which was reversed to a relaxation by treatment with phentolamine. On the other hand, the distal arteries responded to low concentrations of dopamine with relaxations and to high concentrations with contractions. The relaxant response was selectively suppressed by treatment with droperidol and reversed to a contraction by SCH23390, but was not influenced by domperidone and propranolol. The amine-induced relaxation was not reduced by removal of the endothelium. The distal arteries, in which dopamine elicited a relaxation, responded to norepinephrine with dose-related contractions, which were suppressed by phentolamine but were not reversed to relaxations. It may be concluded that dopamine contracts human gastroepiploic arteries of the proximal portion, due to a predominant activation of alpha-adrenoceptors, and dilates the distal arteries by acting preferentially on dopaminergic DA1-receptors, possibly residing in smooth muscle. In the distal arteries, the ability of norepinephrine to activate alpha-adrenoceptors appears to be evidently higher than that of dopamine.