High-altitude acclimation increases the triacylglycerol/fatty acid cycle at rest and during exercise.

Abstract

High-altitude acclimation alters lipid metabolism during exercise, but it is unknown whether this involves changes in rates of lipolysis or reesterification, which form the triacylglycerol/fatty acid (TAG/FA) cycle. We combined indirect calorimetry with [2-(3)H]glycerol and [1-(14)C]palmitate infusions to simultaneously measure total lipid oxidation, lipolysis, and rate of appearance (R(a)) of nonesterified fatty acids (NEFA) in high-altitude-acclimated (HA) rats exercising at 60% maximal O(2) uptake (VO(2 max)). During exercise, relative total lipid oxidation (%VO(2)) equaled sea-level control (SL) values; however, acclimation greatly stimulated lipolysis (+75%) but had no effect on R(a) NEFA. As a result, TAG/FA cycling increased (+119%), due solely to an increase in recycling (+144%) within adipocytes. There was no change in either group in these variables with the transition from rest to exercise. We conclude that, in HA, 1) acclimation is a potent stimulator of lipolysis; 2) rats do not modify TAG/FA cycling with the transition to exercise; and 3) in normoxia, HA and SL derive the same fraction of their total energy from lipids and carbohydrates.

9 Figures and Tables

Statistics

0200400'03'05'07'09'11'13'15'17
Citations per Year

1,025 Citations

Semantic Scholar estimates that this publication has 1,025 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{McClelland2001HighaltitudeAI, title={High-altitude acclimation increases the triacylglycerol/fatty acid cycle at rest and during exercise.}, author={Grant B. McClelland and Peter W. Hochachka and Shannon P. Reidy and Jean Michel Weber}, journal={American journal of physiology. Endocrinology and metabolism}, year={2001}, volume={281 3}, pages={E537-44} }