Kinetic and quantitative measurements of catecholamine transport in chromaffin ghosts using a glassy carbon electrode
✍ Scribed by Susan Hayflick; Robert G. Johnson; Sally E. Carty; Antonio Scarpa
- Publisher
- Elsevier Science
- Year
- 1982
- Tongue
- English
- Weight
- 990 KB
- Volume
- 126
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
A method for the on-line kinetic measurement of net catecholamine uptake and release in ghosts derived from bovine chromaffin granules is described. Changes in free catecholamine concentration in 1 to 2 ml of media containing chromaffin ghosts were continuously measured through the amperometric detection of their oxidation products through a glassy carbon electrode set at 0.5-V potential vs a reference electrode. Parallel measurements of catecholamine uptake and release in the ghosts under various metabolic conditions show a good quantitative agreement between the values obtained with the electrode and those obtained through highperformance liquid chromatography after separation of the ghosts from the medium. Initial velocities of ATP-dependent uptake of epinephrine, norepinephrine, dopamine, and isoprotemol by the ghosts are shown. This method permits, for the first time, quantitation of unidirectional movement of catecholamines in the presence of minute quantities of biological samples. The advantages, limitations, and suitability of this method to measure catecholamine transport in other systems are discussed.