| Autor: |
Margaret Demeny, Edward W. Lowman, Naftchi Ne, Eugene S. Flamm |
| Rok vydání: |
1976 |
| Předmět: |
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| DOI: |
10.1016/b978-0-08-020588-5.50052-7 |
| Popis: |
Publisher Summary Elevated norepinephrine (NE) levels in traumatized spinal cords were implicated in the formation of the hemorrhagic necrosis or were thought to reflect the ingress of circulating amines as a result of disruption of the blood-spinal cord barrier rather than release from descending adrenergic fibers. The present study was undertaken to resolve the controversy concerning the role of catecholamines in traumatized spinal cord. Analysis of monoamine oxidase (MAO) activity in vitro demonstrates that one hour after impact activity of the enzyme is significantly reduced. The reduction in specific activity of DA after contusion of the spinal cord also indicates that the activity of tyrosine hydroxylase, the rate-limiting enzyme in the biosynthesis of NE, is reduced. Since the incorporation of radioactivity into 3H-DA is reduced using the precursors 3H-tyrosine and -3H -dopa it follows that the activity of L-amino acid decarboxylase (L-AAD) is also impaired. In vitro provided with all co-factors including oxygen, dopamine β-hydroxylase (DβH) activity in the spinal cord after impact remains unchanged; within the time interval of the experiment little protein denaturation has taken place. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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