Abstract: FR-PO942
Age-Related Changes in Nuclear Reduced Glutathione Levels in Rat Kidney Cortex and Medulla
Session Information
- Geriatric Nephrology
November 03, 2017 | Location: Hall H, Morial Convention Center
Abstract Time: 10:00 AM - 10:00 AM
Category: Geriatric Nephrology
- 901 Geriatric Nephrology
Authors
- Zamlauski-Tucker, Marianna J., Ball State University, Muncie, Indiana, United States
- Ye, Bingwei, Ball State University, Muncie, Indiana, United States
Background
Aging is associated with changes in the cell related to oxidative stress caused by free radicals produced in aerobic metabolism. Maintenance of reduced glutathione (GSH), the major antioxidant inside cells, provides protection against cell damage caused by free radicals. Although age-related changes in GSH levels in cell organelles, such as the mitochondria, have been reported in previous studies, there is limited information on GSH levels in the cell nucleus and age. The present study was undertaken to investigate the effect of age on changes in nuclear GSH levels in rat kidney cortex and medulla.
Methods
Young (3 months of age) and Old (22 months of age) female Lewis rats were used. The kidneys were harvested from anesthetized rats after being perfused with isotonic saline via a catheter in the abdominal aorta. The kidneys were separated into cortical and medullary sections and homogenized in isotonic saline. Differential centrifugation was used to isolate the nuclear fractions. GSH and oxidized glutathione (GSSG) levels were measured in the fractions using a spectrophotometric assay, and expressed as nmol/g kidney wet weight. Total GSH was determined from the sum of GSH and GSSG expressed in GSH equivalents. The redox ratio (i.e., GSH/GSSG) was also determined. Differences were evaluated using a a Student's t Test.
Results
There was a significant decrease in GSH, GSSG and TOTAL GSH levels with age in the nucleus from rat kidney cortex. There was not a significant decrease in the aforementioned variables with age in the nucleus from rat kidney medulla. The redox ratio was not changed with age in either the kidney cortex or medulla.
Conclusion
The findings indicate that nuclei from the rat kidney cortex do undergo a significant decrease in the antioxidant glutathione with age. This indicates the nucleus from rat kidney cortex is experiencing increased oxidative stress and thus, damage with age.
Age-Related Changes in Nuclear Glutathione Levels in Rat Kidney Cortex and Medulla
| GSH nmol/g kidney wet wt | GSSG nmol/g kidney wet wt | TOTAL GSH nmol/g kidney wet wt | GSH/GSSG (Redox Ratio) | ||
| Young rats (n = 6) | Cortex | 310 ± 22 | 272 ± 49 | 811 ± 127 | 1.3 ± 0.2 |
| Medulla | 213 ± 31 | 312 ± 83 | 837 ± 167 | 1.0 ± 0.3 | |
| Old rats (n = 6) | Cortex | 203 ± 22 * | 126 ± 40 * | 455 ± 40 * | 2.5 ± 0.6 |
| Medulla | 158 ± 22 | 130 ± 43 | 419 ± 103 | 2.1 ± 0.6 |
All data expressed as X +/- SEM. * Significantly different (p<0.05) from Young rats.