Glycerol kinetics with parenteral lipid emulsions (long-chain triglycerides, medium-chain triglycerides, and structured lipids) in rats

D. Drews, M. D. Schluter, Thomas Stein

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Several studies have reported that parenteral lipid emulsions containing medium-chain triglycerides (MCT) and structured lipids (SL) are better utilized than those containing long-chain triglycerides (LCT). The objective of this study was to test the hypothesis that parenteral LCT require more extensive modification via hydrolysis and reesterification (triglyceride-free fatty acid [TG-FFA] recycling) for effective utilization, whereas MCT and SL do not. As an index of TG-FFA cycling activity, we measured glycerol and palmitate kinetics in rats (204 to 243 g) fed parenterally one of three isocaloric (250 kcal/kg/d) isonitrogenous (1.5 g N/kg/d) diets with half of the nonprotein energy from glucose and the rest from either LCT, LCT plus MCT, or SL for 5 days. Two experiments were performed. On day 5, rats were given a 7- to 8-hour infusion of either 5H2 Glycerol and 1-14C Palmitate bound to albumin to measure palmitate and glycerol kinetics (experiment 1), or U-13C glucose to determine the proportion of endogenous glycerol production derived from glucose (experiment 2). Data are presented as means ± SEM. Endogenous glycerol production was significantly higher with LCT (11.33 ± 2.89 mmol/kg/h) than with SL (2.91 ± 0.62 mmol/kg/h). The value for the physical mixture of LCT plus MCT (5.46 ± 1.29 mmol/kg/h) fell midway between that for LCT and SL (P = NS). There were no significant differences in palmitate kinetics or oxidation. The increased glycerol production is due to the mobilization of endogenous triglyceride and is consistent with a higher rate of TG-FFA cycling being involved in the metabolism of LCT than of SL. The energy expended in TG-FFA cycling with LCT can account for the apparent poorer caloric effectiveness of LCT when compared with SL.

Original languageEnglish (US)
Pages (from-to)743-748
Number of pages6
JournalMetabolism
Volume42
Issue number6
DOIs
StatePublished - Jan 1 1993
Externally publishedYes

Fingerprint

Emulsions
Glycerol
Triglycerides
Lipids
Palmitates
Nonesterified Fatty Acids
Glucose
Recycling

All Science Journal Classification (ASJC) codes

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology

Cite this

@article{85e0c5639f5e497faef54477527d1f17,
title = "Glycerol kinetics with parenteral lipid emulsions (long-chain triglycerides, medium-chain triglycerides, and structured lipids) in rats",
abstract = "Several studies have reported that parenteral lipid emulsions containing medium-chain triglycerides (MCT) and structured lipids (SL) are better utilized than those containing long-chain triglycerides (LCT). The objective of this study was to test the hypothesis that parenteral LCT require more extensive modification via hydrolysis and reesterification (triglyceride-free fatty acid [TG-FFA] recycling) for effective utilization, whereas MCT and SL do not. As an index of TG-FFA cycling activity, we measured glycerol and palmitate kinetics in rats (204 to 243 g) fed parenterally one of three isocaloric (250 kcal/kg/d) isonitrogenous (1.5 g N/kg/d) diets with half of the nonprotein energy from glucose and the rest from either LCT, LCT plus MCT, or SL for 5 days. Two experiments were performed. On day 5, rats were given a 7- to 8-hour infusion of either 5H2 Glycerol and 1-14C Palmitate bound to albumin to measure palmitate and glycerol kinetics (experiment 1), or U-13C glucose to determine the proportion of endogenous glycerol production derived from glucose (experiment 2). Data are presented as means ± SEM. Endogenous glycerol production was significantly higher with LCT (11.33 ± 2.89 mmol/kg/h) than with SL (2.91 ± 0.62 mmol/kg/h). The value for the physical mixture of LCT plus MCT (5.46 ± 1.29 mmol/kg/h) fell midway between that for LCT and SL (P = NS). There were no significant differences in palmitate kinetics or oxidation. The increased glycerol production is due to the mobilization of endogenous triglyceride and is consistent with a higher rate of TG-FFA cycling being involved in the metabolism of LCT than of SL. The energy expended in TG-FFA cycling with LCT can account for the apparent poorer caloric effectiveness of LCT when compared with SL.",
author = "D. Drews and Schluter, {M. D.} and Thomas Stein",
year = "1993",
month = "1",
day = "1",
doi = "10.1016/0026-0495(93)90243-H",
language = "English (US)",
volume = "42",
pages = "743--748",
journal = "Metabolism: Clinical and Experimental",
issn = "0026-0495",
publisher = "W.B. Saunders Ltd",
number = "6",

}

Glycerol kinetics with parenteral lipid emulsions (long-chain triglycerides, medium-chain triglycerides, and structured lipids) in rats. / Drews, D.; Schluter, M. D.; Stein, Thomas.

In: Metabolism, Vol. 42, No. 6, 01.01.1993, p. 743-748.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Glycerol kinetics with parenteral lipid emulsions (long-chain triglycerides, medium-chain triglycerides, and structured lipids) in rats

AU - Drews, D.

AU - Schluter, M. D.

AU - Stein, Thomas

PY - 1993/1/1

Y1 - 1993/1/1

N2 - Several studies have reported that parenteral lipid emulsions containing medium-chain triglycerides (MCT) and structured lipids (SL) are better utilized than those containing long-chain triglycerides (LCT). The objective of this study was to test the hypothesis that parenteral LCT require more extensive modification via hydrolysis and reesterification (triglyceride-free fatty acid [TG-FFA] recycling) for effective utilization, whereas MCT and SL do not. As an index of TG-FFA cycling activity, we measured glycerol and palmitate kinetics in rats (204 to 243 g) fed parenterally one of three isocaloric (250 kcal/kg/d) isonitrogenous (1.5 g N/kg/d) diets with half of the nonprotein energy from glucose and the rest from either LCT, LCT plus MCT, or SL for 5 days. Two experiments were performed. On day 5, rats were given a 7- to 8-hour infusion of either 5H2 Glycerol and 1-14C Palmitate bound to albumin to measure palmitate and glycerol kinetics (experiment 1), or U-13C glucose to determine the proportion of endogenous glycerol production derived from glucose (experiment 2). Data are presented as means ± SEM. Endogenous glycerol production was significantly higher with LCT (11.33 ± 2.89 mmol/kg/h) than with SL (2.91 ± 0.62 mmol/kg/h). The value for the physical mixture of LCT plus MCT (5.46 ± 1.29 mmol/kg/h) fell midway between that for LCT and SL (P = NS). There were no significant differences in palmitate kinetics or oxidation. The increased glycerol production is due to the mobilization of endogenous triglyceride and is consistent with a higher rate of TG-FFA cycling being involved in the metabolism of LCT than of SL. The energy expended in TG-FFA cycling with LCT can account for the apparent poorer caloric effectiveness of LCT when compared with SL.

AB - Several studies have reported that parenteral lipid emulsions containing medium-chain triglycerides (MCT) and structured lipids (SL) are better utilized than those containing long-chain triglycerides (LCT). The objective of this study was to test the hypothesis that parenteral LCT require more extensive modification via hydrolysis and reesterification (triglyceride-free fatty acid [TG-FFA] recycling) for effective utilization, whereas MCT and SL do not. As an index of TG-FFA cycling activity, we measured glycerol and palmitate kinetics in rats (204 to 243 g) fed parenterally one of three isocaloric (250 kcal/kg/d) isonitrogenous (1.5 g N/kg/d) diets with half of the nonprotein energy from glucose and the rest from either LCT, LCT plus MCT, or SL for 5 days. Two experiments were performed. On day 5, rats were given a 7- to 8-hour infusion of either 5H2 Glycerol and 1-14C Palmitate bound to albumin to measure palmitate and glycerol kinetics (experiment 1), or U-13C glucose to determine the proportion of endogenous glycerol production derived from glucose (experiment 2). Data are presented as means ± SEM. Endogenous glycerol production was significantly higher with LCT (11.33 ± 2.89 mmol/kg/h) than with SL (2.91 ± 0.62 mmol/kg/h). The value for the physical mixture of LCT plus MCT (5.46 ± 1.29 mmol/kg/h) fell midway between that for LCT and SL (P = NS). There were no significant differences in palmitate kinetics or oxidation. The increased glycerol production is due to the mobilization of endogenous triglyceride and is consistent with a higher rate of TG-FFA cycling being involved in the metabolism of LCT than of SL. The energy expended in TG-FFA cycling with LCT can account for the apparent poorer caloric effectiveness of LCT when compared with SL.

UR - http://www.scopus.com/inward/record.url?scp=0027211725&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027211725&partnerID=8YFLogxK

U2 - 10.1016/0026-0495(93)90243-H

DO - 10.1016/0026-0495(93)90243-H

M3 - Article

C2 - 8510520

AN - SCOPUS:0027211725

VL - 42

SP - 743

EP - 748

JO - Metabolism: Clinical and Experimental

JF - Metabolism: Clinical and Experimental

SN - 0026-0495

IS - 6

ER -