大鼠脑组织中不同部位单胺类神经递质含量的HPLC测定

单胺类神经递质,多巴胺(DA)、去甲肾上腺素(NA)和肾上腺素(A)是哺乳动物和人类中枢重要的信息传递物质。了解脑组织中各部位单胺类神经递质的含量对于研究其生理功能、有关疾病的诊断和药物及手术疗效的评价均有重要的意义。     

高效液相色谱/电化学法测定大鼠血液和脑组织中单胺类物质的含量

建立了高效液相色谱／电化学检测法测定大鼠脑组织和血液中单胺递质及其代谢产物的方法。能同时测定去甲肾上腺素（NE）、肾上腺素（E）、3,4-二羟基苯乙酸（DOPAC）、多巴胺（DA）、高香草酸（HAV）、5-羟色胺（5-HT）,并能和内标3,4-二羟卞胺（DHBA）分离良好。本方法快速、简便,回收率为92％-105％,线性范围2．8-680ng／mL,检出限为0．05ng（S／N=3）。本方法已应用在服用中药的大鼠下丘脑组织及血液的测定中,数据显示,本法能满足测定要求。     

微柱液相色谱-电化学法检测鼠纹状体单胺类物质的含量

单胺类神经递质 ( Monoamines) ,包括儿茶酚胺 ( Catecholamine)和 5 -羟色胺 ( Serotonin) ,在中枢神经系统中起重要作用 .对其含量的准确测定在基础研究和临床诊断中均具有重要的意义 .微透析是 2 0世纪 80年代发展起来的活体取样技术 [1] ,为脑功能的研究提供了极为有力的手段 ,本实验室在此方面进行了多年的研究 [2 ,3] .微透析与液相色谱电化学检测联用[4 ] ,可测定神经细胞外液递质的含量及释放量 ,据此可对一系列重要的生理、病理和药理现象做出解释 .但使用常规高效液相色谱柱 ( =4.6mm i.d.)尚存在不足之处 .首先 ,透析液中神经…     

Simultaneous determination of monoamines in rat brain with Pt/MWCNTs@Pdop hybrid nanocomposite using capillary electrophoresis— amperometric detection

In this article, polydopamine (Pdop) functionalized multiwalled carbon nanotubes (MWCNTs@Pdop) were firstly synthesized and employed as the template for the dispersion of Pt nanoparticles to form Pt/MWCNTs@Pdop hybrid nanocomposite. The characterizations of the Pt/MWCNTs@Pdop were investigated by SEM, transmission electron microscopy, x‐ray diffraction, and voltammetry. Based upon the Pt/MWCNTs@Pdop nanocomposite, a modified carbon disk electrode was fabricated and successfully applied to the simultaneous detection of four important monoamines, including dopamine, epinephrine, norepinephrine, and serotonin, using capillary electrophoresis—amperometric detection system. Compared with the bare electrode, the four analytes at the Pt/MWCNTs@Pdop electrode exhibited higher sensitivity, broad linear responses from 0.5 to 1.0 × 10² nmol/L. The detection limits (S/N = 3) were lower than 9.2 × 10^?10 mol/L. More importantly, the effect of noise exposure on monoamines (MAs) in hippocampus and hypothalamus was investigated for the first time. Compared with the control group, the levels of the MAs all varied to different extents after rats receiving the same noise stimulation. The results showed that the proposed method could be applied to the determination of low levels of MAs in biological samples and screening the target molecules for the diagnosis and treatment of various related diseases.     

Determination of Total Monoamines in Rat Brain via Nanotubes Based Human Monoamine Oxidase B Biosensor

A specific and sensitive electrochemical biosensor with human monoamine oxidase B (hMAO B) as biological receptor and a MnO₂ modified nanomaterial based transducer system has been developed and optimised. Best results for the biosensor were achieved when using enzyme immobilisation with a dialysis membrane (regenerated cellulose, molecular weight cut‐off 14000) and a 20 % (m/m) MnO₂ modified multi‐walled carbon nanotubes (MWCNTs, ratio of fluid to solid compounds of 1 : 0.7 (m/m)) paste electrode smoothed with a glassy carbon paste (GCP, ratio 1 : 3.6 (m/m)) containing the same mediator concentration. The biosensor was operated in a flow injection analysis (FIA) system with Sørensen phosphate buffer (33 mM, pH 7.5) and amperometric detection at a fixed potential of +400 mV vs. Ag/AgCl. The developed sensor underwent validation using phenylethylamine (PEA) as standard substrate showing linearity between 5.0 and 400 µM PEA and limits of detection and quantification of 1.5 and 5.0 µM PEA, respectively. The sensor was successfully tested for the determination of total monoamines in rat brain calculated as PEA equivalents showing a result of 1.2 µg/g brain tissue (n=3, relative standard deviation 4.4 %).     

Photoreduction of imines. An environmentally friendly approach to obtain amines

The photoreduction of different imines to amines in alcoholic solvents is reported. The reduction involves a versatile and chemoselective methodology that is environmentally friendly in that it avoids the use of metal hydrides and other dangerous reducing agents.