Abstract
A pulse ([14C]palmitate)-chase ([3H]palmitate) approach was used to study intramuscular triglyceride (imTG) fatty acid and plasma free fatty acid (FFA) kinetics during exercise at ~45% peak O2 consumption in 12 adults. Vastus lateralis muscle was biopsied before and after 90 min of bicycle exercise; 3H2O production, breath 14CO2 excretion and lipid oxidation (indirect calorimetry) rates were measured during exercise. Results: during exercise, 8.2 ± 1.2 and 8.4 ± 0.7 μmol·kg-1·min-1 of imTG fatty acids and plasma FFA, respectively, were oxidized according to isotopic measurements. The sum of these two values was not different (P =0.6) from lipid oxidation by indirect calorimetry (15.4 ± 1.6 μmol·kg-1·min-1); the isotopic and indirect calorimetry values were correlated (r = 0.79, P < 0.005). During exercise, imTG turnover rate was 0.32 ± 0.07%/min (6.0 ± 2.0 μmol of imTG·kg wet muscle-1·min-1) and plasma FFA were incorporated into imTG at a rate of 0.7 ± 0.1 μmol·kg wet muscle-1·min-1. The imTG pool size did not change during exercise. This pulse-chase, dual tracer appears to be a reasonable approach to measure oxidation and synthesis kinetics of imTG.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2057-2064 |
| Number of pages | 8 |
| Journal | Journal of Applied Physiology |
| Volume | 89 |
| Issue number | 5 |
| State | Published - 2000 |
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Keywords
- [C]palmitate
- Body composition
- Free fatty acids
ASJC Scopus subject areas
- Physiology
- Endocrinology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Kinetics of intramuscular triglyceride fatty acids in exercising humans. / Guo, Z.; Burguera, B.; Jensen, Michael Dennis.
In: Journal of Applied Physiology, Vol. 89, No. 5, 2000, p. 2057-2064.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Kinetics of intramuscular triglyceride fatty acids in exercising humans
AU - Guo, Z.
AU - Burguera, B.
AU - Jensen, Michael Dennis
PY - 2000
Y1 - 2000
N2 - A pulse ([14C]palmitate)-chase ([3H]palmitate) approach was used to study intramuscular triglyceride (imTG) fatty acid and plasma free fatty acid (FFA) kinetics during exercise at ~45% peak O2 consumption in 12 adults. Vastus lateralis muscle was biopsied before and after 90 min of bicycle exercise; 3H2O production, breath 14CO2 excretion and lipid oxidation (indirect calorimetry) rates were measured during exercise. Results: during exercise, 8.2 ± 1.2 and 8.4 ± 0.7 μmol·kg-1·min-1 of imTG fatty acids and plasma FFA, respectively, were oxidized according to isotopic measurements. The sum of these two values was not different (P =0.6) from lipid oxidation by indirect calorimetry (15.4 ± 1.6 μmol·kg-1·min-1); the isotopic and indirect calorimetry values were correlated (r = 0.79, P < 0.005). During exercise, imTG turnover rate was 0.32 ± 0.07%/min (6.0 ± 2.0 μmol of imTG·kg wet muscle-1·min-1) and plasma FFA were incorporated into imTG at a rate of 0.7 ± 0.1 μmol·kg wet muscle-1·min-1. The imTG pool size did not change during exercise. This pulse-chase, dual tracer appears to be a reasonable approach to measure oxidation and synthesis kinetics of imTG.
AB - A pulse ([14C]palmitate)-chase ([3H]palmitate) approach was used to study intramuscular triglyceride (imTG) fatty acid and plasma free fatty acid (FFA) kinetics during exercise at ~45% peak O2 consumption in 12 adults. Vastus lateralis muscle was biopsied before and after 90 min of bicycle exercise; 3H2O production, breath 14CO2 excretion and lipid oxidation (indirect calorimetry) rates were measured during exercise. Results: during exercise, 8.2 ± 1.2 and 8.4 ± 0.7 μmol·kg-1·min-1 of imTG fatty acids and plasma FFA, respectively, were oxidized according to isotopic measurements. The sum of these two values was not different (P =0.6) from lipid oxidation by indirect calorimetry (15.4 ± 1.6 μmol·kg-1·min-1); the isotopic and indirect calorimetry values were correlated (r = 0.79, P < 0.005). During exercise, imTG turnover rate was 0.32 ± 0.07%/min (6.0 ± 2.0 μmol of imTG·kg wet muscle-1·min-1) and plasma FFA were incorporated into imTG at a rate of 0.7 ± 0.1 μmol·kg wet muscle-1·min-1. The imTG pool size did not change during exercise. This pulse-chase, dual tracer appears to be a reasonable approach to measure oxidation and synthesis kinetics of imTG.
KW - [C]palmitate
KW - Body composition
KW - Free fatty acids
UR - http://www.scopus.com/inward/record.url?scp=0033768061&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033768061&partnerID=8YFLogxK
M3 - Article
C2 - 11053362
AN - SCOPUS:0033768061
VL - 89
SP - 2057
EP - 2064
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 5
ER -