Measurement of precursor enrichment for calculating intramuscular triglyceride fractional synthetic rate

Xiao Jun Zhang, Noe A. Rodriguez, Lijian Wang, Demidmaa Tuvdendorj, Zhanpin Wu, Alai Tan, David Herndon, Robert R. Wolfe

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Our goal was to assess the validity of the enrichments of plasma free palmitate and intramuscular (IM) fatty acid metabolites as precursors for calculating the IM triglyceride fractional synthetic rate. We infused U- 13C16-palmitate in anesthetized rabbits for 3 h and sampled adductor muscle of legs using both freeze-cut and cut-freeze approaches. We found that IM free palmitate enrichment (0.70 ± 0.07%) was lower (P < 0.0001) than IM palmitoyl-CoA enrichment (2.13 ± 0.17%) in samples taken by the freeze-cut approach. The latter was close (P = 0.33) to IM palmitoyl-carnitine enrichment (2.42 ± 0.16%). The same results were obtained from the muscle samples taken by the cut-freeze approach, except the enrichment of palmitoyl-CoA (2.21 ± 0.08%) was lower (P = 0.02) than that of palmitoyl-carnitine (2.77 ±0.17%). Plasma free palmitate enrichment was ∼2-fold that of IM palmitoyl-CoA enrichment and palmitoyl-carnitine enrichment (P < 0.001). These findings indicate that plasma free palmitate overestimated IM precursor enrichment owing to in vivo IM lipid breakdown, whereas IM free palmitate enrichment underestimated the precursor enrichment because of lipid breakdown during muscle sampling and processing. IM palmitoyl-carnitine enrichment was an acceptable surrogate of the precursor enrichment because it was less affected by in vitro lipid breakdown after sampling.

Original languageEnglish (US)
Pages (from-to)119-125
Number of pages7
JournalJournal of Lipid Research
Volume53
Issue number1
DOIs
StatePublished - Jan 2012

Fingerprint

Palmitates
Triglycerides
Carnitine
Palmitoyl Coenzyme A
Muscle
Lipids
Plasmas
Muscles
Sampling
Metabolites
Leg
Fatty Acids
Rabbits
Processing

Keywords

  • Fatty acyl-carnitine
  • Fatty acyl-coenzyme A
  • Mass spectrometry
  • Rabbits
  • Stable isotopes

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Endocrinology

Cite this

Measurement of precursor enrichment for calculating intramuscular triglyceride fractional synthetic rate. / Zhang, Xiao Jun; Rodriguez, Noe A.; Wang, Lijian; Tuvdendorj, Demidmaa; Wu, Zhanpin; Tan, Alai; Herndon, David; Wolfe, Robert R.

In: Journal of Lipid Research, Vol. 53, No. 1, 01.2012, p. 119-125.

Research output: Contribution to journalArticle

Zhang, Xiao Jun ; Rodriguez, Noe A. ; Wang, Lijian ; Tuvdendorj, Demidmaa ; Wu, Zhanpin ; Tan, Alai ; Herndon, David ; Wolfe, Robert R. / Measurement of precursor enrichment for calculating intramuscular triglyceride fractional synthetic rate. In: Journal of Lipid Research. 2012 ; Vol. 53, No. 1. pp. 119-125.
@article{eaa349beb98c4d09ad2467195180aba5,
title = "Measurement of precursor enrichment for calculating intramuscular triglyceride fractional synthetic rate",
abstract = "Our goal was to assess the validity of the enrichments of plasma free palmitate and intramuscular (IM) fatty acid metabolites as precursors for calculating the IM triglyceride fractional synthetic rate. We infused U- 13C16-palmitate in anesthetized rabbits for 3 h and sampled adductor muscle of legs using both freeze-cut and cut-freeze approaches. We found that IM free palmitate enrichment (0.70 ± 0.07{\%}) was lower (P < 0.0001) than IM palmitoyl-CoA enrichment (2.13 ± 0.17{\%}) in samples taken by the freeze-cut approach. The latter was close (P = 0.33) to IM palmitoyl-carnitine enrichment (2.42 ± 0.16{\%}). The same results were obtained from the muscle samples taken by the cut-freeze approach, except the enrichment of palmitoyl-CoA (2.21 ± 0.08{\%}) was lower (P = 0.02) than that of palmitoyl-carnitine (2.77 ±0.17{\%}). Plasma free palmitate enrichment was ∼2-fold that of IM palmitoyl-CoA enrichment and palmitoyl-carnitine enrichment (P < 0.001). These findings indicate that plasma free palmitate overestimated IM precursor enrichment owing to in vivo IM lipid breakdown, whereas IM free palmitate enrichment underestimated the precursor enrichment because of lipid breakdown during muscle sampling and processing. IM palmitoyl-carnitine enrichment was an acceptable surrogate of the precursor enrichment because it was less affected by in vitro lipid breakdown after sampling.",
keywords = "Fatty acyl-carnitine, Fatty acyl-coenzyme A, Mass spectrometry, Rabbits, Stable isotopes",
author = "Zhang, {Xiao Jun} and Rodriguez, {Noe A.} and Lijian Wang and Demidmaa Tuvdendorj and Zhanpin Wu and Alai Tan and David Herndon and Wolfe, {Robert R.}",
year = "2012",
month = "1",
doi = "10.1194/jlr.M019901",
language = "English (US)",
volume = "53",
pages = "119--125",
journal = "Journal of Lipid Research",
issn = "0022-2275",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "1",

}

TY - JOUR

T1 - Measurement of precursor enrichment for calculating intramuscular triglyceride fractional synthetic rate

AU - Zhang, Xiao Jun

AU - Rodriguez, Noe A.

AU - Wang, Lijian

AU - Tuvdendorj, Demidmaa

AU - Wu, Zhanpin

AU - Tan, Alai

AU - Herndon, David

AU - Wolfe, Robert R.

PY - 2012/1

Y1 - 2012/1

N2 - Our goal was to assess the validity of the enrichments of plasma free palmitate and intramuscular (IM) fatty acid metabolites as precursors for calculating the IM triglyceride fractional synthetic rate. We infused U- 13C16-palmitate in anesthetized rabbits for 3 h and sampled adductor muscle of legs using both freeze-cut and cut-freeze approaches. We found that IM free palmitate enrichment (0.70 ± 0.07%) was lower (P < 0.0001) than IM palmitoyl-CoA enrichment (2.13 ± 0.17%) in samples taken by the freeze-cut approach. The latter was close (P = 0.33) to IM palmitoyl-carnitine enrichment (2.42 ± 0.16%). The same results were obtained from the muscle samples taken by the cut-freeze approach, except the enrichment of palmitoyl-CoA (2.21 ± 0.08%) was lower (P = 0.02) than that of palmitoyl-carnitine (2.77 ±0.17%). Plasma free palmitate enrichment was ∼2-fold that of IM palmitoyl-CoA enrichment and palmitoyl-carnitine enrichment (P < 0.001). These findings indicate that plasma free palmitate overestimated IM precursor enrichment owing to in vivo IM lipid breakdown, whereas IM free palmitate enrichment underestimated the precursor enrichment because of lipid breakdown during muscle sampling and processing. IM palmitoyl-carnitine enrichment was an acceptable surrogate of the precursor enrichment because it was less affected by in vitro lipid breakdown after sampling.

AB - Our goal was to assess the validity of the enrichments of plasma free palmitate and intramuscular (IM) fatty acid metabolites as precursors for calculating the IM triglyceride fractional synthetic rate. We infused U- 13C16-palmitate in anesthetized rabbits for 3 h and sampled adductor muscle of legs using both freeze-cut and cut-freeze approaches. We found that IM free palmitate enrichment (0.70 ± 0.07%) was lower (P < 0.0001) than IM palmitoyl-CoA enrichment (2.13 ± 0.17%) in samples taken by the freeze-cut approach. The latter was close (P = 0.33) to IM palmitoyl-carnitine enrichment (2.42 ± 0.16%). The same results were obtained from the muscle samples taken by the cut-freeze approach, except the enrichment of palmitoyl-CoA (2.21 ± 0.08%) was lower (P = 0.02) than that of palmitoyl-carnitine (2.77 ±0.17%). Plasma free palmitate enrichment was ∼2-fold that of IM palmitoyl-CoA enrichment and palmitoyl-carnitine enrichment (P < 0.001). These findings indicate that plasma free palmitate overestimated IM precursor enrichment owing to in vivo IM lipid breakdown, whereas IM free palmitate enrichment underestimated the precursor enrichment because of lipid breakdown during muscle sampling and processing. IM palmitoyl-carnitine enrichment was an acceptable surrogate of the precursor enrichment because it was less affected by in vitro lipid breakdown after sampling.

KW - Fatty acyl-carnitine

KW - Fatty acyl-coenzyme A

KW - Mass spectrometry

KW - Rabbits

KW - Stable isotopes

UR - http://www.scopus.com/inward/record.url?scp=84455172908&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84455172908&partnerID=8YFLogxK

U2 - 10.1194/jlr.M019901

DO - 10.1194/jlr.M019901

M3 - Article

VL - 53

SP - 119

EP - 125

JO - Journal of Lipid Research

JF - Journal of Lipid Research

SN - 0022-2275

IS - 1

ER -