Quantitative microdialysis of dopamine in the striatum: effect of circadian variation.

摘要: Two quantitative microdialysis methods were used to determine the concentration of extracellular dopamine in anterior striatum rat. In first method, slow perfusion flow rate was at 57 nl/min and dialysate samples collected every 90 min for 18 h assayed (DA), DOPAC (3,4-dihydroxy-phenylacetic acid), homovanillic acid (HVA) 5-hydroxy-indoleacetic (5-HIAA). There a significant increase during dark cycle compared with light (14.7 ± 1 nM vs. 9.3 0.7 nM; mean SEM; P < 0.0001), indicating possible circadian variations DA. steady decrease level HVA, no change 5-HIAA. For point no-net-flux animals perfused 4 concentrations DA or DOPAC, bracketing concentrations. The using this method 10.2 1.7 17.4 2.6 μM, respectively. vivo recoveries as derived from slope linear regression curves 72 3% 43 5%. These values shown be significantly different (P 0.001). Both gave similar results striatum.