Simultaneous determination of catecholamines and their metabolites related to Alzheimer's disease in human urine

Abstract

A simple and specific high-performance liquid chromatography method coupled with fluorescence detection (HPLC-FL) has been developed for the simultaneous determination of L-3,4-dihydroxyphenylalanine, norepinephrine, dopamine, epinephrine and 3,4-dihydroxyphenylacetic acid in human urine. The samples were derivatized by 1,2-diphenylethylenediamine with isoprenaline as internal standard. The factors affecting the fluorescence yield were investigated, including the reaction and separation conditions. The catecholamine derivatives were separated on a Kromasil C(18) column with methanol and sodium acetate buffer as mobile phase. The limits of detection for all catecholamines ranged from 0.2 to 1.1 ng/mL. The linear ranges were from 2.5 to 200 ng/mL except 3,4-dihydroxyphenylacetic acid from 5 to 200 ng/mL. The intra- and interday RSDs for all catecholamines were 1.0-8.0 and 2.1-14%, respectively. The method was successfully applied to determine the catecholamines in human urine from 14 Alzheimer's disease patients and 14 healthy volunteers. It was concluded that the mean levels of catecholamines in urine of Alzheimer's disease patients were all lower than those in healthy volunteers. The cluster analysis and independent samples T-test were used to distinguish the Alzheimer's disease patients and healthy volunteers.

Potential links between neurological disease and Tako-Tsubo cardiomyopathy: A literature review

“…Also inflammation can induce oxidative damage, especially via microglia, leading to increased ROS formation and the resulting damage to lipid, proteins, and nucleic acids [41]. In this context several strategies could be adopted in order to reduce oxidative stress; a larger catecholamine consumption in neuronal tissue might act as an antioxidant; conversely, lower levels of catecholamines were found in urine of Alzheimer disease patients when compared with healthy volunteers [42].…”

Indirect Chemiluminescence-based Determination of Catecholamines in Pharmaceutical Formulations by Furandicarboxylate Derivative as a Novel Blue Fluorescer in Peroxyoxalate-H2O2 System

“…A variety of techniques, such as spectrophotometry, 3,4 fluorometry, [5][6][7][8] electrochemistry 5,9,10 and tandem mass spectrometry 11 have been utilized for the detection of CAs. However, some of these methods lack sensitivity and selectivity or require derivation steps or sophisticated instruments.…”

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“…Liu et al, 16 developed a simple and specific HPLC method coupled with fluorescence detection for the simultaneous determination of NE, DA, and E in human urine. They derivatized the samples with 1,2-diphenylethylenediamine and used the isoprenaline as internal standard.…”