Independence of exercise hyperpnea and acidosis during high-intensity exercise in ponies.
Abstract: We investigated arterial PCO2 (PaCO2) and pH (pHa) responses in ponies during 6-min periods of high-intensity treadmill exercise. Seven normal, seven carotid body-denervated (2 wk-4 yr) (CBD), and five chronic (1-2 yr) lung (hilar nerve)-denervated (HND) ponies were studied during three levels of constant load exercise (7 mph-11%, 7 mph-16%, and 7 mph-22% grade). Mean pHa for each group of ponies became alkaline in the first 60 s (between 7.45 and 7.52) (P less than 0.05) at all work loads. At 6 min pHa was at or above rest at 7 mph-11%, moderately acidic at 7 mph-16% (7.32-7.35), and markedly acidic at 7 mph-22% (7.20-7.27) for all groups of ponies. Yet with no arterial acidosis at 7 mph 11%, normal ponies decreased PaCO2 below rest (delta PaCO2) by 5.9 Torr at 90 s and 7.8 Torr by 6 min of exercise (P less than 0.05). With a progressively more acid pHa at the two higher work loads in normal ponies, delta PaCO2 was 7.3 and 7.8 Torr by 90 s and 9.9 and 11.4 Torr by 6 min, respectively (P less than 0.05). CBD ponies became more hypocapnic than the normal group at 90 s (P less than 0.01) and tended to have greater delta PaCO2 at 6 min. The delta PaCO2 responses in normal and HND ponies were not significantly different (P greater than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)
Publication Date: 1986-03-01 PubMed ID: 3082847DOI: 10.1152/jappl.1986.60.3.1016Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- U.S. Gov't
- Non-P.H.S.
- Research Support
- U.S. Gov't
- P.H.S.
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research investigates the responses of arterial carbon dioxide pressure (PaCO2) and arterial pH (pHa) in ponies during high-intensity exercise. Despite varying levels of exercise intensity, ponies show an increase in pHa (alkalizarion) at first before transitioning to acidic conditions, while their PaCO2 levels largely decrease.
Research Methodology
- The study included three groups of ponies: seven normal, seven with denervated carotid bodies (impacting the body’s ability to detect changes in oxygen, carbon dioxide, and pH), and five with chronic lung denervation.
- Ponies underwent three levels of constant load exercise, at 7 mph but with varying incline grades of 11%, 16%, and 22%.
Findings
- In all groups, the mean arterial pH started to rise initially, indicating a movement towards alkaline conditions, but later shifted towards acidity at higher workloads. This shift was more pronounced at the 16% and 22% grades. The initial alkalosis might be due to the initial hyperventilation during exercise leading to excessive carbon dioxide loss.
- There was a decrease in arterial carbon dioxide pressure, or PaCO2, across all exercise levels for normal ponies. This decrease was more significant with increased exercise intensity even though the pHa was moving towards acidity.
- By the end of the exercise (6 minutes), all groups exhibited an increased hypocapnia, which is a state of reduced carbon dioxide in the blood. This was particularly prominent in the ponies with denervated carotid bodies.
- The study showed no significant differences in carbon dioxide response between normal ponies and those with lung denervation.
Significance
- The findings provide insights into the biological responses in ponies during high-intensity exercise, particularly regarding alterations in arterial pH and carbon dioxide pressure levels.
- The study also shows a dissociation between exercise hyperpnea (increased breathing rate) and acidosis, suggesting that these two factors are independent of each other during high-intensity exercise in ponies.
Cite This Article
APA
Pan LG, Forster HV, Bisgard GE, Murphy CL, Lowry TF.
(1986).
Independence of exercise hyperpnea and acidosis during high-intensity exercise in ponies.
J Appl Physiol (1985), 60(3), 1016-1024.
https://doi.org/10.1152/jappl.1986.60.3.1016 Publication
Researcher Affiliations
MeSH Terms
- Acidosis / blood
- Acidosis / physiopathology
- Animals
- Arteries
- Bicarbonates / blood
- Carbon Dioxide / blood
- Carotid Body / physiology
- Denervation
- Heart Rate
- Horses
- Hydrogen-Ion Concentration
- Hyperventilation / blood
- Hyperventilation / physiopathology
- Lactates / blood
- Lactic Acid
- Lung / innervation
- Partial Pressure
- Physical Exertion
- Respiration
- Time Factors
Grant Funding
- 5-F32-HL06899-02-CLN / NHLBI NIH HHS
- HL-25739 / NHLBI NIH HHS
Citations
This article has been cited 3 times.- Lindinger MI, Waller AP. Physicochemical Analysis of Mixed Venous and Arterial Blood Acid-Base State in Horses at Core Temperature during and after Moderate-Intensity Exercise.. Animals (Basel) 2022 Jul 22;12(15).
- Kesavan K, Frank P, Cordero DM, Benharash P, Harper RM. Neuromodulation of Limb Proprioceptive Afferents Decreases Apnea of Prematurity and Accompanying Intermittent Hypoxia and Bradycardia.. PLoS One 2016;11(6):e0157349.
- Sheel AW, Richards JC, Foster GE, Guenette JA. Sex differences in respiratory exercise physiology.. Sports Med 2004;34(9):567-79.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
