NO对大鼠中脑腹侧被盖区DA神经元的调节

实验观察了微量注射 NOS抑制剂 L -NAME及微量联合注射 NO的前体 L-精氨酸( L-Arg) L-NAME于大鼠中脑腹侧被盖区( VTA)对该部位多巴胺神经元的调节。发现VTA注射 L -NAME( 1 mg/ 5μL )后 ,伏隔核( Acb)多巴胺 ( DA )代谢产物—双羟苯乙酸( DOPAC)水平升高到注射前的 1 2 2 .5% ( P <0 .0 0 1 ) ,小剂量注射 L-NAME( 0 .2 mg/ 5μL)对伏隔核 DOPAC水平无明显影响 ;同样方法联合注射 L-Arg( 3 0 0 μg/ 5μL) L-NAME( 1 mg/5μL)后 ,伏隔核 DOPAC水平无明显变化。结论 :VTA微量注射 L-NAME兴奋了该部位的DA神经元 ,而 L -Arg L -NAME联合注射 ,却不能影响 DA神经元的活动 ,说明 NO可以通过L-Arg-NOS-NO途径参与 VTA多巴胺神经元的调节

The Regulation of NO in Ventral Tegmental Area on Dopamine Neurons in Rats

The effect of microinjection of the nitric oxide synthase(NOS) inhibitor Nomega-nitro-L-arginine methyl ester(L-NAME) and L-arginine L-NAME into the ventral tegmental area(VTA) on the activity of dopamine neurons in VTA were studied in rats. Results:It was observed that in aneasthetized rats microinjection of L-NAME 1mg increased the level of 3,4-dihydroxyphenylacetic acid (DOPAC) to 122.5%(P<0.001) of control value in the nucleus accumbens (Acb).The microinjection of L-NAME 0.2mg had no significant effect on the Acb DOPAC level.There was no change in the level of DOPAC in Acb when coadministration of L-arginine 300ug with L-NAME 1mg. Conclusion: Our data suggested that microinjection of L-NAME into VTA could exert an excitatory action on the dopamine neurons in VTA; Coadministration of L-arginine with L-NAME completely prevented the effect of L-NAME. Our results showed that NO is involved in the regulation of dopamine neurons in VTA by L-arginine-NOS-NO pathway.