A new method is presented for the detection of phentolamine by high performance liquid chromatography with electrochemical detection. The electrochemical detector was used in the oxidative mode at +900 mV potential versus Ag/AgCl reference. The on-column detection limit for phentolamine using this m
Assay of brain aldehyde dehydrogenase activity using high-performance liquid chromatography with electrochemical detection
โ Scribed by Olof Tottmar
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 470 KB
- Volume
- 158
- Category
- Article
- ISSN
- 0003-2697
No coin nor oath required. For personal study only.
โฆ Synopsis
A method has been developed for assay of aldehyde dehydrogenase (ALDH) in brain tissue or in other tissues containing low ALDH-activity. The aldehyde of dopamine was used as the substrate, and the 3,4-dihydroxyphenylacetic acid formed was measured using high-performance liquid chromatography (HPLC) with electrochemical detection. The aldehyde was prepared enzymatically by incubating dopamine with a monoamine-oxidase preparation from rat liver mitochondria in the presence of Na+-bisulfite in 10 mM K+-phosphate buffer (pH 7.5). Rat brain homogenates were incubated in 50 mM Na+-pyrophosphate buffer (pH 8.8) containing 0.5 mM NAD+ and 5 fiM aldehyde. The reaction was terminated with perchloric acid containing Na+-bisulfite to trap excess of the aldehyde. The acid supematants were injected on a reverse-phase HPLC column and elution was performed with citrate buffer, pH 2.50. The method permits assay with l-10 mg of brain tissue with an overall precision of 3%. The assay rate was 5-6 samples per hour. o 1986 Academic Press, Inc.
๐ SIMILAR VOLUMES
We developed a method to determine dihydrofolate reductase (DHFR) activity at pH 7.4 (37ยฐC) by monitoring its product, tetrahydrofolate (H 4 folate), using HPLC with electrochemical detection. After the assay mixture was deproteinized by 0.5 M perchlolic acid, the H 4 folate concentration was measur
An assay for measuring dihydroorotase activity was devised. Radiolabeled substrate and product were separated by high-performance liquid chromatography using a reverse-phase column with ion-pairing, and the radioactivity was quantitated by flow detection. 8 1%~ Academic Press. Inc.
Cysteamine is currently used to treat children with the inherited disorder nephropathic cystinosis. A method for the quantitative determination of this aminothiol in human plasma is presented. Whole plasma was reduced with sodium borohydride to convert disulfides to thiols. Cysteamine was then separ