大鼠脑中P物质对突触体D-[(3)H]天冬氨酸转运的刺激作用。

Stimulation of synaptosomal D-[(3)H]aspartate transport by substance P in rat brain.

作者信息

Healy J, Downes A, McBean G J

机构信息

Department of Biochemistry, University College Dublin, Belfield, 4, Dublin, Ireland.

出版信息

Neurosci Lett. 2000 Aug 25;290(2):113-6. doi: 10.1016/s0304-3940(00)01318-5.

DOI:10.1016/s0304-3940(00)01318-5

PMID:10936690

Abstract

The effect of the neuropeptide, substance P, on the transport of D-[(3)H]aspartate into rat striatal synaptosomes was studied. Almost 90% of the total transport of D-[(3)H]aspartate was sodium-dependent and the maximum rate (V(max)) of this transport was increased by 34% of control by 2.5 nM substance P (EC(50)=0.52 nM). In contrast, sodium-independent transport was inhibited by substance P. The NK(1) antagonist, L706303 (500 nM) blocked the stimulation of D-[(3)H]aspartate transport by 2.5 nM substance P, but did not alter D-aspartate uptake in the absence of substance P. These results indicate that high affinity glutamate transporters in the brain may be under positive regulation by substance P, and suggest a previously-unidentified mechanism of control of glutamate transport.

摘要

研究了神经肽P物质对D-[(3)H]天冬氨酸转运至大鼠纹状体突触体的影响。D-[(3)H]天冬氨酸的总转运中近90%依赖于钠，该转运的最大速率（V(max)）在2.5 nM P物质作用下比对照增加了34%（半数有效浓度（EC(50)）=0.52 nM）。相反，不依赖钠的转运受到P物质的抑制。NK(1)拮抗剂L706303（500 nM）可阻断2.5 nM P物质对D-[(3)H]天冬氨酸转运的刺激作用，但在无P物质时不改变D-天冬氨酸的摄取。这些结果表明，大脑中的高亲和力谷氨酸转运体可能受P物质的正向调节，并提示了一种先前未被识别的谷氨酸转运控制机制。