Smith P A, Dombro K R, Zidichouski J
J Pharmacol Exp Ther. 1984 Jul;230(1):221-7.
The food dye erythrosin B has been reported to inhibit the neuronal uptake of catecholamines. To test this hypothesis we examined the effect of the dye on the responses of neurons in amphibian sympathetic ganglia to both dopamine and epinephrine. Although the hyperpolarizations induced by both catecholamines were potentiated by the conventional uptake blocker, desipramine (0.5 microM), low doses of erythrosin B (1-10 microM) produced an irreversible blockade. It was therefore not possible to evaluate the hypothesis that the dye might block catecholamine uptake. Xanthine dyes such as erythrosin B have also been reported to inhibit Na-K-adenosine triphosphatase. In agreement with this possibility we found that erythrosin B promoted irreversible inhibition of the (nicotinic) acetylcholine after-hyperpolarization. This response is generated by the electrogenic activity of the Na+ pump. Neither this Na+ pump inhibition nor erythrosin-induced membrane hyperpolarization appeared to account for the effect of the dye on catecholamine responses. The irreversible antagonism of epinephrine and dopamine by erythrosin was specific in that hyperpolarizing responses to muscarinic antagonists such as methacholine were relatively insensitive to the dye. It is therefore concluded that erythrosin B selectively antagonizes responses to catecholamines in amphibian sympathetic ganglia. No information as to the exact molecular mechanism of this antagonism is available from the present experiments.
据报道，食用色素赤藓红B可抑制儿茶酚胺的神经元摄取。为了验证这一假设，我们研究了该色素对两栖类交感神经节神经元对多巴胺和肾上腺素反应的影响。尽管常规摄取阻滞剂地昔帕明（0.5微摩尔）可增强两种儿茶酚胺诱导的超极化，但低剂量的赤藓红B（1 - 10微摩尔）会产生不可逆的阻断作用。因此，无法评估该色素可能阻断儿茶酚胺摄取这一假设。据报道，诸如赤藓红B之类的黄嘌呤色素也可抑制钠钾 - 三磷酸腺苷酶。与此可能性相符，我们发现赤藓红B促进了（烟碱型）乙酰胆碱超极化后电位的不可逆抑制。这种反应是由钠泵的生电活性产生的。这种钠泵抑制以及赤藓红诱导的膜超极化似乎都不能解释该色素对儿茶酚胺反应的影响。赤藓红对肾上腺素和多巴胺的不可逆拮抗作用具有特异性，因为对毒蕈碱拮抗剂如乙酰甲胆碱的超极化反应对该色素相对不敏感。因此得出结论，赤藓红B选择性拮抗两栖类交感神经节对儿茶酚胺的反应。目前的实验尚无关于这种拮抗作用确切分子机制的信息。
