Na-K-ATPase activity decreases with aging in female rat brain synaptosomes
| Autor: | Allen I. Arieff, Cosmo L. Fraser |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Senescence
Aging medicine.medical_specialty Physiology Sodium Central nervous system chemistry.chemical_element NA K EXCHANGING ATPASE Rats Sprague-Dawley Internal medicine medicine Animals Enzyme Inhibitors Ouabain Na k atpase activity Synaptosome Chemistry Brain Biological Transport medicine.disease Rat brain Rats Enzyme Activation medicine.anatomical_structure Endocrinology Potassium Female Sodium-Potassium-Exchanging ATPase Hyponatremia Synaptosomes |
| Zdroj: | American Journal of Physiology-Renal Physiology. 281:F674-F678 |
| ISSN: | 1522-1466 1931-857X |
| DOI: | 10.1152/ajprenal.2001.281.4.f674 |
| Popis: | To understand why elderly females are better able to tolerate hyponatremia, we measured brain Na-K-ATPase activity to determine whether this adaptive mechanism was affected by age. Using synaptosomes from 2-, 12-, and 19-mo-old female rats, we show in our results that Na-K-ATPase activity changes with age in female rats. Enzyme activity was significantly ( P = 0.0026) reduced (17%) from 0.416 ± 0.01 at 2 mo to 0.345 ± 0.01 at 12 mo and reduced ( P = 0.0001) (34%) to 0.274 ± 0.02 μmol · min−1· mg protein−1at 19 mo. To determine whether this decrease was due to reduced transport function of the Na-K-ATPase pump, we performed potassium transport using rubidium (86Rb+) as tracer. Ouabain-sensitive potassium uptake at 2 mo was 16.18 ± 1.31 nmol/mg protein, was significantly ( P = 0.0063) reduced (39%) to 9.79 ± 1.44 nmol/mg at 12 mo, and was significantly ( P = 0.0003) reduced (62%) to 6.12 ± 1.05 nmol/mg protein at 19 mo. On the contrary, Na-K-ATPase activity remained elevated in males during aging. These data suggest that the Na-K-ATPase pump in female rat brain synaptosomes is decreased with increased age, and that this decrease is probably due in part to decreased potassium transport by the Na-K-ATPase pump. |
| Databáze: | OpenAIRE |
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