| Altitude acclimatization attenuates plasma ammonia accumulation during submaximal exercise. | |
| | |
MedLine Citation:
|
PMID: 3308809 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
This study examined the effects of acclimatization to 4,300 m altitude on changes in plasma ammonia concentrations with 30 min of submaximal [75% maximal O2 uptake (VO2max)] cycle exercise. Human test subjects were divided into a sedentary (n = 6) and active group (n = 5). Maximal uptake (VO2max) was determined at sea level and at high altitude (HA; 4,300 m) after acute (t less than 24 h) and chronic (t = 13 days) exposure. The VO2max of both groups decreased 32% with acute HA when compared with sea level. In the sedentary group, VO2max decreased an additional 16% after 13 days of continuous residence at 4,300 m, whereas VO2max in the active group showed no further change. In both sedentary and active subjects, plasma ammonia concentrations were increased (P less than 0.05) over resting levels immediately after submaximal exercise at sea level as well as during acute HA exposure. With chronic HA exposure, the active group showed no increase in plasma ammonia immediately after submaximal exercise, whereas the postexercise ammonia in the sedentary group was elevated but to a lesser extent than at sea level or with acute HA exposure. Thus postexercise plasma ammonia concentration was decreased with altitude acclimatization when compared with ammonia concentrations following exercise performed at the same relative intensity at sea level or acute HA. This decrease in ammonia accumulation may contribute to enhanced endurance performance and altered substrate utilization with exercise following acclimatization to altitude. |
| | |
Authors:
|
P M Young; P B Rock; C S Fulco; L A Trad; V A Forte; A Cymerman |
Related Documents
:
|
16891649 - Mini-incision for strictly retroperitoneal nephrectomy in living kidney donation vs fla... 1623889 - Oxygen transport during exercise at altitude and the lactate paradox: lessons from oper... 3084449 - Low acute hypoxic ventilatory response and hypoxic depression in acute altitude sickness. 6542519 - After effects of chronic hypoxia on cardiac output and muscle blood flow at rest and ex... 8620949 - High altitude exposure reduces bronchial responsiveness to hypo-osmolar aerosol in lowl... 21177269 - National and international interlaboratories comparisons: a tool for the validation of ... 18398589 - Characteristics of the respiratory mechanical and muscle function of competitive breath... 17646269 - Molecular and histological analysis of a new rat model of experimental knee osteoarthri... 20013559 - Effect of glycemic index meals on recovery and subsequent endurance capacity. |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 63 ISSN: 8750-7587 ISO Abbreviation: J. Appl. Physiol. Publication Date: 1987 Aug |
Date Detail:
|
Created Date: 1987-11-09 Completed Date: 1987-11-09 Revised Date: 2008-11-21 |
Medline Journal Info:
|
Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 758-64 Citation Subset: IM; S |
Affiliation:
|
Altitude Research Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acclimatization* Adult Altitude* Ammonia / blood* Blood Glucose / analysis Fatty Acids, Nonesterified / blood Glycerol / blood Humans Insulin / blood Lactates / blood Lactic Acid Male Oxygen Consumption Physical Exertion* |
| Chemical | |
Reg. No./Substance:
|
0/Blood Glucose; 0/Fatty Acids, Nonesterified; 0/Lactates; 11061-68-0/Insulin; 50-21-5/Lactic Acid; 56-81-5/Glycerol; 7664-41-7/Ammonia |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Circulating vasoactive substances and hemodynamic adjustments at birth in lambs.
Next Document: Pulmonary arterial transit times.