著者

大井 清

出版者

九州歯科学会

雑誌

九州歯科学会雑誌 (ISSN:03686833)

巻号頁・発行日

vol.47, no.1, pp.235-247, 1993-02-25 (Released:2017-12-21)

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Using the technique of in vivo microdialysis, extracellular concentrations of dopamine, 3, 4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were determined in the nucleus accumbens and ventral tegmental area, while Sprague-Dawley rats underwent lidocaine perfusion and intravenation. The microdialysis probe had semipermeable cellulose tubes (molecular weight cutoff 50, 000 : O. D. 0.22mm). Perfusion was started 12 hours after implantation of the microdialysis probe under a freely-moving condition. Measurement of the extracellular concentrations of dopamine, DOPAC and HVA was made at 20 minute intervals, which was started 120 minutes after the onset of the perfusion. Dopamine, DOPAC and HVA were quantified by a high-performance liquid chromatography coupled with an electrochemical detector. The results were as follows : 1. Extracellular dopamine levels decreased in perfusion of 10^<-3> M lidocaine for 100 minutes in nucleus accumbens and ventral tegmental area of rat brain, but they did not change in perfusion of 10^<-4>&acd;10^<-6> M lidocaine. 2. Extracellular dopamine levels did not change in intravenation of 0.74mg/min lidocaine for 20 minutes in nucleus accumbens and ventral tegmental area of rat brain. 3. It is assumed that the high concentration lidocaine inhibited mesolimbic dopamine neuron activity, but the lidocaine did not inhibit mesolimbic dopamine neuron activity when it's concentration was less than convulsion threshold.