# Aging Mitochondrial Fragmentation and Metabolic Inflexibility

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA BERKELEY · 2020 · $573,642

## Abstract

Summary/Abstract
Metabolic flexibility refers to the ability to switch between carbohydrate (CHO) and fat oxidation in response to
changing physiological conditions. A mixed-model design is proposed to interrogate the hypothesis that the loss of
metabolic flexibility in aging is of mitochondrial origin. The design calls for studies on intact humans, human skeletal
muscle (SM) and white adipose tissue (WAT) as well as on rat and mouse SM and WAT. A segment of the effort on
cells and organelles isolated from young and old lab rodents will be necessary to perform extensive respiratory control
studies as well as studies of mitochondrial dynamics and composition, whereas because of sample size limitations,
studies an human mitochondrial preparations will be involve selective analyses. To test the main hypothesis four cohorts
of humans will be studied: sedentary (< 2 hr vigorous PA/wk) and physically active (>5 hr PA/wk) young healthy
controls (21-35 yr), older sedentary and physically active individuals (60-80 yr) of age. Tissues will be harvested from
analogous rat populations, 3-4 month (mo) and 21-23 mo old male and female F344 rats and young (2-3 mo) and old (15
mo) GPR81 null mice (Aim 4).

## Key facts

- **NIH application ID:** 9970153
- **Project number:** 5R01AG059715-03
- **Recipient organization:** UNIVERSITY OF CALIFORNIA BERKELEY
- **Principal Investigator:** GEORGE Austin BROOKS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $573,642
- **Award type:** 5
- **Project period:** 2018-08-15 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9970153

## Citation

> US National Institutes of Health, RePORTER application 9970153, Aging Mitochondrial Fragmentation and Metabolic Inflexibility (5R01AG059715-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9970153. Licensed CC0.

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