delta-Aminolevulinic acid synthetase: regulation of activity in various tissues of the aging rat
| Autor: | Diana S. Beattie, Ching-I P. Lin, James R. Paterniti |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Male
medicine.medical_specialty Aging Biophysics Mitochondria Liver Mitochondrion Kidney Biochemistry chemistry.chemical_compound Basal (phylogenetics) Internal medicine medicine Animals Molecular Biology chemistry.chemical_classification Ethanol biology Myocardium Heart δ-aminolevulinic acid Enzyme assay Rats medicine.anatomical_structure Enzyme Endocrinology chemistry Metabolic regulation Liver Organ Specificity Enzyme Induction biology.protein 5-Aminolevulinate Synthetase |
| Zdroj: | Archives of biochemistry and biophysics. 191(2) |
| ISSN: | 0003-9861 |
| Popis: | The basal and ethanol-induced activities of the rate-limiting enzyme of heme biosynthesis, δ-aminolevulinic acid (ALA) synthetase were measured in the liver, heart, kidney, and brain of young, adult, and aged Sprague-Dawley rats. When assayed in whole mitochondria derived from either fed or 24-h fasted animals, the basal levels of hepatic ALA synthetase activity decreased dramatically as a function of age. An equivalent decrease was seen in the ethanol-induced activity although the ratio of induced to basal activities did not change with age. In the heart, ALA synthetase activity also decreased significantly during aging. The activity was not induced by ethanol and was decreased markedly by fasting. By contrast, kidney ALA synthetase activity showed no age-related changes. The activity was unaffected by fasting and showed a variable induction response to ethanol. Brain ALA synthetase activity displayed a significant age-dependent decrease in its activity which was neither affected by fasting nor sensitive to induction by ethanol. The data presented are consistent with the hypothesis that ALA synthetase activity is subject to metabolic regulation. Further, they indicate that while the enzyme activity is regulated in a tissuespecific manner, a time-dependent decrease is a general feature of the aging animal. |
| Databáze: | OpenAIRE |
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