Del Arco A, Segovia G, Prieto L, Mora F
Department of Physiology, Faculty of Medicine, University Complutense, Cuidad Universitaria, s/n 28040 Madrid, Spain.
Mech Ageing Dev. 2001 Apr 15;122(4):401-14. doi: 10.1016/s0047-6374(00)00252-9.
Using microdialysis, the effects of endogenous glutamate on extracellular concentrations of taurine, in striatum and nucleus accumbens of the awake rat during the normal process of aging were investigated. The glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) was perfused through the microdialysis probe to increase the endogenous concentration of glutamate. Young (2-4 months), middle aged (12-14 months), aged (27-32 months) and very aged (37 months) male Wistar rats were used. PDC (1, 2 and 4 mM) produced a dose-related increase of extracellular concentrations of glutamate and taurine in striatum and nucleus accumbens in all groups of age. Increases of glutamate, but not of taurine, decreased during aging in striatum. In nucleus accumbens there were no age-related changes in the increases of glutamate and taurine induced by PDC. In all age groups, increases of extracellular taurine were significantly correlated with increases of extracellular glutamate. However, when these taurine-glutamate correlations for all groups of age were compared, no statistical differences were found. These results show first that a decrease in the increases of glutamate produced by the glutamate reuptake inhibitor in striatum, but not in nucleus accumbens, is produced by age; second that glutamate-taurine interaction in striatum and nucleus accumbens does not change during the normal process of aging.
采用微透析技术，研究了内源性谷氨酸对清醒大鼠纹状体和伏隔核中牛磺酸细胞外浓度在正常衰老过程中的影响。通过微透析探针灌注谷氨酸摄取抑制剂L-反式吡咯烷-2,4-二羧酸（PDC），以提高内源性谷氨酸浓度。使用了年轻（2 - 4个月）、中年（12 - 14个月）、老年（27 - 32个月）和极老龄（37个月）的雄性Wistar大鼠。PDC（1、2和4 mM）在所有年龄组的纹状体和伏隔核中均引起谷氨酸和牛磺酸细胞外浓度呈剂量相关的增加。在纹状体中，随着衰老，谷氨酸的增加量减少，但牛磺酸的增加量未减少。在伏隔核中，PDC诱导的谷氨酸和牛磺酸增加量没有与年龄相关的变化。在所有年龄组中，细胞外牛磺酸的增加与细胞外谷氨酸的增加显著相关。然而，当比较所有年龄组的这些牛磺酸 - 谷氨酸相关性时，未发现统计学差异。这些结果首先表明，年龄导致谷氨酸再摄取抑制剂在纹状体而非伏隔核中产生的谷氨酸增加量减少；其次表明，在正常衰老过程中，纹状体和伏隔核中的谷氨酸 - 牛磺酸相互作用没有改变。
