Parsons L H, Justice J B
Emory University, Department of Chemistry, Atlanta, GA 30322.
Brain Res. 1993 Mar 26;606(2):195-9. doi: 10.1016/0006-8993(93)90984-u.
The effects of local application of serotonin (5-HT) on extracellular levels of dopamine (DA) in the nucleus accumbens (N. ACC) were assessed using in vivo microdialysis. At a perfusate flow rate of 0.3 microliter/min the baseline dialysate concentration of DA was 2.1 +/- 0.7 nM (mean +/- S.E.M.; n = 5) and significantly increased to 142 +/- 18%, 220 +/- 47% and 332 +/- 35% of baseline when 0.1 microM, 0.2 microM and 0.4 microM concentrations of 5-HT were included in the perfusate. Perfusate 5-HT concentrations below 0.1 microM had no effect on dialysate DA. The in vivo dialysis efficiency for 5-HT was found to be 39 +/- 12%, and thus the concentrations of 5-HT reaching the extracellular space at the surface of the dialysis membrane were estimated to be 40, 80 and 160 nM for the 0.1, 0.2 and 0.4 microM 5-HT perfusates, respectively. The serotonin-induced increase in dialysate DA was attenuated by co-perfusion of 0.4 microM 5-HT with 4 microM concentrations of pindolol (a relatively non-specific 5-HT1 antagonist; 151 +/- 7% vs. 332 +/- 35% baseline dialysate DA for 5-HT/antagonist and 5-HT-only perfusates, respectively), LY 53,857 (a specific 5-HT2 antagonist; 130 +/- 17% vs. 332 +/- 35%) and MDL 7222 (a specific 5-HT3 antagonist; 143 +/- 19% vs. 332 +/- 35%).(ABSTRACT TRUNCATED AT 250 WORDS)
采用体内微透析技术评估了局部应用5-羟色胺（5-HT）对伏隔核（N. ACC）细胞外多巴胺（DA）水平的影响。在灌注液流速为0.3微升/分钟时，DA的基线透析液浓度为2.1±0.7纳摩尔/升（平均值±标准误；n = 5），当灌注液中加入0.1微摩尔/升、0.2微摩尔/升和0.4微摩尔/升浓度的5-HT时，DA浓度显著升高至基线的142±18%、220±47%和332±35%。灌注液中5-HT浓度低于0.1微摩尔/升时对透析液DA无影响。发现5-HT的体内透析效率为39±12%，因此对于0.1、0.2和0.4微摩尔/升的5-HT灌注液，到达透析膜表面细胞外空间的5-HT浓度分别估计为40、80和160纳摩尔/升。5-HT诱导的透析液DA增加被0.4微摩尔/升的5-HT与4微摩尔/升的吲哚洛尔（一种相对非特异性的5-HT1拮抗剂；5-HT/拮抗剂和仅5-HT灌注液的透析液DA分别为基线的151±7%和332±35%）、LY 53,857（一种特异性5-HT2拮抗剂；130±17%对332±35%）和MDL 7222（一种特异性5-HT3拮抗剂；143±19%对332±35%）共同灌注所减弱。（摘要截断于250字）
