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Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
The plasma ammonia response to cycle exercise in COPD.
L D Calvert1, S J Singh, P L Greenhaff
1Dept of Respiratory Medicine, Institute for Lung Health, Glenfield Hospital, Leicester, UK. lori.calvert@uhl-tr.nhs.uk
The European Respiratory Journal
|December 21, 2007
Summary
Plasma ammonia levels increase during exercise in chronic obstructive pulmonary disease (COPD) patients, potentially indicating muscle fatigue. This response varies, offering insights into muscle metabolism during physical activity.
Area of Science:
- Exercise Physiology
- Pulmonary Medicine
- Biochemistry
Background:
- Chronic obstructive pulmonary disease (COPD) is associated with exercise intolerance.
- Muscle adenine nucleotide metabolism is crucial for energy production during exercise.
- Plasma ammonia levels may serve as a biomarker for muscle metabolic stress.
Purpose of the Study:
- To investigate the plasma ammonia response to exercise in COPD patients.
- To explore the relationship between plasma ammonia and muscle adenine nucleotide metabolism.
- To determine if plasma ammonia changes can predict muscle fatigue in COPD.
Main Methods:
- 25 stable COPD patients and 13 healthy controls underwent incremental and constant-work rate cycle exercise tests.
- Arterialised venous blood samples were collected at rest, during exercise, and post-exercise for ammonia and lactate analysis.
- Muscle inosine-5'-monophosphate (IMP) formation was assessed in relation to ammonia changes.
Main Results:
- COPD patients exhibited significantly lower peak incremental work rates compared to controls.
- Plasma ammonia increased during exercise in both groups, but two distinct patterns emerged in COPD patients.
- A significant correlation was observed between plasma ammonia increase and muscle IMP formation in COPD subjects.
Conclusions:
- Plasma ammonia concentration increases during exercise in COPD patients, even at lower work rates.
- The plasma ammonia response during exercise may reflect alterations in muscle adenine nucleotide metabolism.
- Monitoring plasma ammonia could offer insights into exercise-induced muscle fatigue in COPD management.
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