吗啡依赖大鼠视皮层GABA及分解代谢酶的变化

Changes of GABA and its catabolic enzymes in the visual cortex of morphine-dependent rats

目的通过对吗啡依赖大鼠视皮层γ-氨基丁酸(GABA)含量及GAD与GABA-T活力的测定,研究吗啡成瘾过程中视皮层γ-氨基丁酸的代谢变化。方法30只SD大鼠分为6组,末次给药前10 min,后10 min,后3 h处死组及相应对照组,每组5只。纸电泳法检测各组大鼠视皮层中GABA含量,分光光度法检测GAD与GABA-T的活力。结果吗啡末次给药前处死组大鼠GABA含量(0.09±0.03)μmol/mg与对照组(0.17±0.05)μmol/mg比较,差异有统计学意义,末次给药后处死组GABA含量回复至对照组水平。结论吗啡依赖形成时视皮层处于去抑制状态。

Objective To investigate the changes of γ-aminobutyfie aeid（GABA） content and glutamie acid deearboxylase （GAD）, γ-aminobutyrie acid transaminase （GABA-T） activity in visual cortex of morphine-dependent rats. Methods Paper eleetrophoresis was employed to detect GABA content in visual cortex and speetrophotometrie method was used to investigate the activity of GAD and GABA-T in each experimental group. Results GABA content in visual cortex of rats decapitated before the last morphine injection was significantly decreased （0.09± 0.03）μmol/mg compared with saline control （0.17± 0.05）μmol/mg. GABA content of rats decapitated after the last morphine injection restored to normal level. Conclusion Visual cortex is in disinhibition with chronic morphine exposure.