Acetyl coenzyme A in the brain: radioenzymatic determination, use of microwaves, and postmortem changes
| Autor: | Stanislav Tuček, Jan Říčný |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
Biophysics
Ischemia Radioimmunoassay Endogeny Amberlite Biochemistry Choline chemistry.chemical_compound Acetyl Coenzyme A medicine Animals Microwaves Molecular Biology Brain Chemistry Chromatography Cell Biology Metabolism medicine.disease Chromatography Ion Exchange Choline acetyltransferase Acetylcholine Freezing point Rats chemistry Postmortem Changes medicine.drug |
| Zdroj: | Analytical biochemistry. 103(2) |
| ISSN: | 0003-2697 |
| Popis: | The radioenzymatic method of acetyl coenzyme A (acetyl-CoA) determination in the brain devised by Shea and Aprison (1977, J. Neurochem. 28 , 51–58.) is based on the principle that tissue acetyl-CoA is incubated with [ 14 C]choline and choline acetyltransferase and the radioactivity of [ 14 C]acetylcholine so formed is measured. The removal of endogenous choline is a necessary preliminary step. The use of a cation exchanger (Amberlite CG-50) was found more suitable for this purpose than the extraction of choline with tetraphenylboron. Blanks could be further reduced when high-voltage electrophoresis was used for separation of [ 14 C]acetylcholine in the final step of the assay. Postmortem ischemia was found to increase the content of acetyl-CoA in the brain. In 3-day-old rats killed by freezing in liquid N 2 , or by decapitation followed by immediate freezing of the head, the content of acetyl-CoA in the brain is 1.82 nmol·g −1 ; it increases to 4.87 nmol·g −1 if the head is separated from the body, kept at room temperature, and frozen after a delay of 1 min. A similar increase (from 1.85 before to 3.87 nmol·g −1 after 2 min of ischemia) is observed in adult rats when microwaves are used to arrest brain metabolism. The content of acetyl-CoA in the brain of adult rats is higher in experiments with decapitation followed by immediate freezing of the head in liquid N 2 than in those using microwave irradiation; it is suggested that the increase occurs during the period of ischemia between decapitation and the fall of brain temperature below the freezing point. |
| Databáze: | OpenAIRE |
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