Phebus L A, Roush M E, Clemens J A
Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, Indiana 46285.
Life Sci. 1990;47(15):1317-23. doi: 10.1016/0024-3205(90)90195-w.
Systemic administration of direct and indirect dopamine agonists resulted in increased extracellular ascorbic acid levels in the striatum and, to a lesser degree, in the nucleus accumbens as measured by in vivo voltammetry. Intraperitoneal d-amphetamine sulfate (5mg/kg) increased ascorbate concentrations in striatal extracellular fluid. Amphetamine also increased extracellular ascorbate levels in the nucleus accumbens although more gradually and to a lesser extent. Intraperitoneal phenethylamine hydrochloride (20 mg/kg) following pargyline hydrochloride pretreatment (20 mg/kg) increased extracellular ascorbate levels in the striatum significantly above the small increase seen in the nucleus accumbens. The direct acting dopamine agonists Ly-141865 and Ly-163502 when given i.p. at 1 mg/kg, resulted in increased extracellular ascorbate concentrations in both brain areas, again with a significantly greater effect in the striatum. These results indicate that brain extracellular ascorbate levels can be modulated by dopaminergic neuro-transmission and that this modulation is quantitatively different in different dopamine-containing brain structures.
通过体内伏安法测量发现，直接和间接多巴胺激动剂的全身给药导致纹状体细胞外抗坏血酸水平升高，伏隔核中的升高程度较小。腹腔注射硫酸右旋苯丙胺（5mg/kg）可增加纹状体细胞外液中的抗坏血酸盐浓度。苯丙胺也会增加伏隔核中的细胞外抗坏血酸水平，不过上升更为缓慢且程度较小。在盐酸帕吉林预处理（20mg/kg）后腹腔注射盐酸苯乙胺（20mg/kg），纹状体中的细胞外抗坏血酸水平显著升高，远高于伏隔核中出现的小幅升高。直接作用的多巴胺激动剂Ly-141865和Ly-163502以1mg/kg腹腔注射时，导致两个脑区的细胞外抗坏血酸盐浓度升高，同样在纹状体中的作用更为显著。这些结果表明，脑内细胞外抗坏血酸水平可受多巴胺能神经传递调节，且这种调节在不同含多巴胺的脑结构中存在量的差异。
