Parenteral Infusion of Long‐ and Medium‐Chain Triglycerides and Reticuloendothelial System Function in Man

Abstract

Previous study demonstrated that patients who received total parenteral nutrition (TPN) with standard intermittent infusion of long chain triglyceride (LCT) at 0.13 g kg-1hr-1 over 10 hr for each of three days showed a significant decline in 99Tc-sulfur colloid (TSC) clearance rate by the reticuloendothelial system (RES). The present studies evaluated eight patients who received the same total lipid dose of LCT infused continuously as in a three-in-one admixture, and another nine patients receiving the same amount of fat as a medium chain triglyceride (MCT)/LCT (75%/25%) emulsion intermittently over 10 hr at 0.13 g kg-1hr-1 for three consecutive days. Patients were given continuous total parenteral nutrition (TPN) comprised of protein, 1.5 g kg-1day-1, and dextrose, 4.5 g kg-1day-1. RES function was examined by measuring the clearance rates of intravenously injected TSC while receiving TPN containing only protein and dextrose, and again after three days of fat infusion. Mean (+/- SEM) clearance rate constants before and after continuous LCT infusion were 0.38 +/- 0.09 and 0.41 +/- 0.08 min-1, respectively, while those before and after intermittent MCT/LCT infusion were 0.50 +/- 0.18 and 0.73 +/- 0.24 min-1, respectively. In contrast to intermittent LCT infusion, the administration of continuous LCT or an intermittent MCT/LCT mixture does not impair TSC clearance by the RES. These findings suggest that condensing the daily period of LCT infusion at standard dosage may exceed the rate of metabolic utilization, resulting in increased fat removal and diminished TSC uptake by the RES.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatic reticuloendothelial function during parenteral nutrition including an MCT/LCT or LCT emulsion after liver transplantation - a double-blind study

“…Opsonins appear not to be involved in HSA-MM clearance, but it is still unclear which receptor may indeed be involved [ 171. Seidner et al [29] and Jensen et al [12] used TSCs in their studies, but these appear unsuitable for macrophage function assessment. In studies by Hirschberg et al [14], TSCs were cleared from the bloodstream with nonsaturable kinetics.…”

Effect of an Enteral Diet Containing Medium-Chain Triglyceride on Protein Metabolism in Septic Rats.

“…However, as MCT are exclusively saturated fatty acids, an essential unsaturated fatty acid such as linoleic acid must be supplemented by blending with LCT for the nutritional requirement of the patients. Several investigators reported that a mixture of intravenously injected MCT/LCT was more advantageous as an energy source under seriously stressful conditions than LCT or glucose [11][12][13]. However, effects of enteral administration of MCT/LCT in sepsis have rarely been reported.…”

“…MCT are oxidized independently of carnitine, whereas LCT require carnitine to be oxidized. Jensen et al [13] suggested that MCT would be a promising fat substrate for septic patients who were carnitine-depleted. As MCT were previously reported to be superior to LCT as an energy source in septic rats [21], in the present study we investigated the effect of MCT administration on protein metabolism in septic rats.…”

“…We used enteral diets that contained fat as 10% of total calories, because we previously had demonstrated this to be the preferable energy ratio of fat in septic rats based on nutritional status [17]. Regarding the mixture ratio of MCT and LCT, several investigators previously used ratios from 1: 1 (MCT : LCT) to 7 : 3 in their studies on surgical nutrition [11][12][13]. We preferred the ratio of 6: 4, a MCT-rich combination, as an intermediate ratio of previous studies.…”

Efeito de emulsão lipídica parenteral composta por mistura de triglicérides de cadeia média e óleos de soja, oliva e peixe sobre a migração e fagocitose de leucócitos de ratos

“…Em estudos experimentais e clínicos, TCL ω-6 foram associados à deficiência de funções de linfócitos, neutrófilos e macrófagos (Waitzberg et al, 1996;Jensen et al, 1990;Sedman et al, 1990;Hamawy et al, 1985;Sobrado et al, 1985;Nordenstrom et al, 1979). TCL ω-6 podem ainda aumentar a intensidade da resposta inflamatória em determinadas condições clínicas (Wanten e Calder, 2007).…”