6-Hydroxydopamine hydrobromide (6-OHDA) is a structural analogue of catecholamines, dopamine and noradrenaline, and exerts its toxic effects on catecholaminergic neurons. The neurotoxin 6-hydroxydopamine continues to constitute a valuable topical tool used chiefly in modeling Parkinson's disease (PD) in the rat [1].
The classical method of intracerebral infusion of 6-Hydroxydopamine hydrobromide, involving a massive destruction of nigrostriatal dopaminergic neurons, is largely used to investigate motor and biochemical dysfunctions in Parkinson's disease [1]
6-Hydroxydopamine hydrobromide undergoes robust auto-oxidation generating cytotoxic H2O2, reactive oxygen species (ROS) and catecholamine quinones which attack endocellular nucleophilic groups [2].
Neurotoxic effects of 6-Hydroxydopamine hydrobromide occur through a two-step mechanism involving accumulation of the toxin into catecholaminergic neurons, followed by alteration of cellular homeostasis and neuronal damage. Intracellular storage of 6-Hydroxydopamine hydrobromide is mediated by the dopamine or noradrenaline membrane transporters (DAT and NAT respectively), which recognize and uptake 6-Hydroxydopamine hydrobromide due to its structural similarity with endogenous catecholamines [3]. 6-Hydroxydopamine hydrobromide is infused unilaterally in the MFB, producing a functional imbalance between the dopaminergic nigrostriatal systems and resulting in motor slowness, indicative of parkinsonian-like akinesia, and typical rotational behaviour in response to dopaminomimetic agents [4].
References:
[1]. Simola N, Morelli M, Carta A R. The 6-hydroxydopamine model of Parkinson's disease[J]. Neurotoxicity research, 2007, 11(3): 151-167.
[2]. Palumbo A, A Napolitano, P Barone and M d'Ischia (1999) Nitrite- and peroxide-dependent oxidation pathways of dopamine: 6-nitrodopamine and 6-hydroxydopamine formation as potential contributory mechanisms of oxidative stress- and nitric oxide-induced neurotoxicity in neuronal degeneration. Chem. Res. Toxicol. 12, 1213-1222.
[3]. Luthman J, A Fredriksson, E Sundstrom, G Jonsson and T.Archer (1989) Selective lesion of central dopamine or noradrenaline neuron systems in the neonatal rat: motor behavior and monoamine alterations at adult stage. Behav. Brain.Res. 33, 267-277.
[4]. Ungerstedt U and G Arbuthnott (1970) Quantitative recording of rotational behavior in rats after 6-hydroxydopamine lesions of the nigrostriatal dopamine system. Brain Res. 24, 485-493.
6-Hydroxydopamine hydrobromide (6-OHDA) 是儿茶酚胺、多巴胺和去甲肾上腺素的结构类似物，对儿茶酚胺能神经元发挥毒性作用。神经毒素 6-羟基多巴胺继续构成一种有价值的局部工具，主要用于模拟大鼠帕金森病 (PD) [1]。
大脑内输注 6-羟基多巴胺氢溴酸盐的经典方法涉及大量破坏黑质纹状体多巴胺能神经元，主要用于研究帕金森病的运动和生化功能障碍[1]
6-羟基多巴胺氢溴酸盐会发生强烈的自氧化，产生细胞毒性 H2O2、活性氧 (ROS) 和儿茶酚胺醌，这些物质会攻击细胞内的亲核基团 [2]。
6-羟基多巴胺氢溴酸盐的神经毒性作用通过两步机制发生，涉及毒素在儿茶酚胺能神经元中的积累，然后是细胞稳态的改变和神经元损伤。 6-羟基多巴胺氢溴酸盐的细胞内储存由多巴胺或去甲肾上腺素膜转运蛋白（分别为 DAT 和 NAT）介导，由于其与内源性儿茶酚胺的结构相似，它们识别和摄取 6-羟基多巴胺氢溴酸盐[3]。 6-羟基多巴胺氢溴酸盐被单侧注入 MFB，在多巴胺能黑质纹状体系统之间产生功能失衡，导致运动迟缓，表明帕金森样运动不能，以及对多巴胺模拟药物反应的典型旋转行为[4].