The Effect of Increasing Levels of Fish Oil-Containing Structured Triglycerides on Protein Metabolism in Parenterally Fed Rats Stressed by Burn Plus Endotoxin

Abstract

This report investigates the effect of various levels of medium-chain/fish oil structured triglycerides on protein and energy metabolism in hypermetabolic rats. Male Sprague-Dawley rats (192 to 226 g) were continuously infused with isovolemic diets that provided 200 kcal/kg per day and 2 g of amino acid nitrogen per kilogram per day. The percentage of nonnitrogen calories as structured triglyceride was varied: no fat, 5%, 15%, or 30%. A 30% long-chain triglyceride diet was also provided as a control to compare the protein-sparing abilities of these two types of fat. Nitrogen excretion, plasma albumin, plasma triglycerides, and whole-body and liver and muscle protein kinetics were determined after 3 days of feeding. Whole-body protein breakdown, flux, and oxidation were similar in all groups. The 15% structured triglyceride diet maximized whole-body protein synthesis (p < .05). Liver fractional synthetic rate was significantly greater in animals receiving 5% of nonprotein calories as structured triglyceride (p < .05). Muscle fractional synthetic rate was unchanged. Plasma triglycerides were markedly elevated in the 30% structured triglyceride-fed rats. The 30% structured triglyceride diet maintained plasma albumin levels better than those diets containing no fat, 5% medium-chain triglyceride/fish oil structured triglycerides, or 30% long-chain triglycerides. Nitrogen excretion was lower in animals receiving 30% of nonnitrogen calories as a structured triglyceride than in those receiving 30% as long-chain triglycerides, but this difference did not reach statistical significance (p = .1). These data suggest that protein metabolism is optimized when structured triglyceride is provided at relatively low dietary fat intakes. (Journal of Parenteral and Enteral Nutrition 17:247-253, 1993)

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References

MacFie J. , Smith RC , Hill GL : Glucose or fat as a nonprotein energy source? Gastroenterology 80:103-107, 1981

Elwyn DH , Kinney JM Gump FE , et al: Some metabolic effects of fat infusion in depleted patients . Metabolism 29:125-132, 1980

Nordenstrom J. , Carpentier YA , Askanazi J. , et al: Metabolic utilization of intravenous fat emulsion during total parenteral nutrition. Ann Surg 196:221-231, 1982

Jeejeebhoy KN , Anderson GH , Nakhooda AF , et al: Metabolic studies in total parenteral nutrition with lipid in man. J Clin Invest 57:125-136, 1976

Baker JP , Detsky AS , Stewart S. , et al: Randomized trial of total parenteral nutrition in critically ill patients: Metabolic effect of varying glucose-lipid ratios as the energy source. Gastroenterology 87:53-59, 1984

Burke JF , Wolfe RR , Mullany CJ , et al: Glucose requirements following burn injury. Parameters of optimal glucose infusion and possible hepatic and respiratory abnormalities following excessive glucose intake. Ann Surg 190:274-285, 1979

Kaufmann RL , Matson CF , Rowberg AH , et al: Defective lipid disposal mechanisms during bacterial infection in rhesus monkeys. Metabolism 25:615-624, 1976

Hamawy KJ , Moldawer LL , Georgieff M. , et al: The effect of lipid emulsions on reticuloendothelial system function in the injured animals. JPEN 9:559-565, 1985

Fischer GW , Hunter KW , Wilson SR , et al: Diminished bacterial defences with Intralipid. Lancet 2:819-820, 1980.

10.

Trocki O. , Heyd TJ , Waymack JP , et al: Effects of fish oil on postburn metabolism and immunity. JPEN 11:521-528, 1987

11.

Sobrado J. , Moldawer LL , Pomposelli JJ , et al: Lipid emulsions and reticuloendothelial system function in healthy and burned guinea pigs. Am J Clin Nutr 42:855-863, 1985

12.

Alexander JW , Saito H. , Trocki O. , et al: The importance of lipid type in the diet after burn injury. Ann Surg 204:1-8, 1986

13.

Mochizuki H. , Trocki O. , Dominioni L. , et al: Optimal content for enteral diets following thermal injury. JPEN 8:638-646, 1984

14.

Teo TC , DeMichele SJ , Selleck KM , et al: Administration of structured lipid composed of MCT and fish oil reduces net protein catabolism in enterally fed burned rats. Ann Surg 210:100-107, 1989

15.

Ling PR , Istfan NW , Lopes SM , et al: Structured lipid made from fish oil and medium-chain triglycerides alters tumor and host metabolism in Yoshida-sarcoma-bearing rats. Am J Clin Nutr 53:1177-1184, 1991

16.

Ling PR , Bistrian BR , Blackburn GL , et al: Effect of fetal growth on maternal protein metabolism in postabsorptive rat. Am J Physiol 252:E380-E390, 1987

17.

Weir JBV : New methods for calculating metabolic rate with special reference to protein metabolism. J Physiol (Lond) 109:1-9, 1949

18.

Waterlow JC , Garlick PJ , Millward DJ : Protein Turnover in Mammalian Tissue and in the Whole Body. North Holland, Amsterdam, 1978, pp 339-370

19.

DeMichele SJ , Karlstad MD , Babayan VK , et al: Enhanced skeletal muscle and liver protein synthesis with structured lipid in enterally fed burned rats. Metabolism 37:787-795, 1988

20.

Garlick PJ , Millward DJ , James WPT : The diurnal response of muscle and liver protein synthesis, in vivo, in meal fed rats. Biochem J 136:935-945, 1973

21.

Gottschlich MM , Alexander JW : Fat kinetics and recommended dietary intake in burns. JPEN 11:80-85, 1987

22.

Wilmore DW , Long JM , Mason AD , et al: Catecholamines: Mediator of the hypermetabolic response to thermal injury. Ann Surg 180:653-669, 1974

23.

Hasselgren PO , Jagenburg R. , Karlstrom L. , et al: Changes of protein metabolism in liver and skeletal muscle following trauma complicated by sepsis . J Trauma 24:224-228, 1984

24.

Goodenough RD , Wolfe RR : Effect of total parenteral nutrition on free fatty acid metabolism in burned patients. JPEN 8:357-360, 1984

25.

Karlstad MD , DeMichele SJ , Istfan N. , et al: Effect of burn and first-pass splanchnic leucine extraction on protein kinetics in rats. Am J Physiol 255:R303-R309, 1988

26.

Munro HN : General aspects of the regulation of protein metabolism by diet and hormones . IN Mammalian Protein Metabolism, Vol 1, Munro HN (ed). Academic Press, New York, 1964, pp 381-481

27.

Mascioli EA , Leader L. , Flores E. , et al: Enhanced survival to endotoxin in guinea pigs fed IV fish oil emulsion. Lipids 23:623-625, 1988

28.

Lutz O. , Lave T. , Frey A. , et al: Activities of lipoprotein lipase and hepatic lipase on long- and medium-chain triglyceride emulsions used in parenteral nutrition. Metabolism 38:507-513, 1989

29.

Mahoney JR , Beutler BA , Le Trang N. , et al: Purification of cachectin, a lipoprotein lipase-suppressing hormone secreted by endotoxin-induced ear 264.7 cells. J Exp Med 161:984-995, 1985

30.

Beutler B. , Mahoney J. , Le Trang N. , et al: Lipopolysaccharide-treated raw 264.7 cells produce a mediator that inhibits lipoprotein lipase in 3T3-L1 cells. J Immunol 134:1673-1675, 1985

31.

Robin AP , Askanazi J. , Greenwood RC , et al: Lipoprotein lipase activity in surgical patients: Influence of trauma and infection. Surgery 90:401-408, 1981

32.

Forbes GB : Splenic lipidosis after administration of intravenous fat emulsions . J Clin Pathol 31:765-771, 1978

33.

Du Toit DF , Villet WT , Heydenrych J. : Fat-emulsion deposition in mononuclear phagocytic system. Lancet 2:898, 1978

34.

DiLuzio NR : Employment of lipids in the measurement and modification of cellular. humoral and immune responses. Adv Lipid Res 10:43-88, 1972

35.

Nordenstrom J. , Jarstrand C. Wiernik A. : Decreased chemotactic and random migration of leukocytes during Intralipid infusion. Am J Clin Nutr 32:2416-2422. 1979

36.

McGiff JC : Prostaglandins. prostacyclin, and thromboxanes . Annu Rev Pharmacol Toxicol 21:479-509, 1981

37.

Murphy MG : Dietary fatty acids and membrane protein function. J Nutr Biochem 1:68-79, 1990

38.

German JB , Lokesh B. , Bruckner GG , et al: Effect of increasing levels of dietary fish oil on tissue lipids and prostaglandin synthesis in the rat. Nutr Res 5:1393-1407, 1985

39.

Nassar BA , Manku MS , Huang YS , et al: The influence of dietary marine oil (POLEPA) and evening primrose oil (EFAMOL) on prostaglandin production by the rat mesenteric vasculature . Prostaglandins Leukotrienes Med 26:253-263, 1987

40.

Billiar TR , Bankey PE , Svingen BA et al: Fatty acid intake and kupffer cell function: Fish oil alters eicosanoid and monokine production to endotoxin stimulation. Surgery 104:343-349, 1988

41.

Endres S. , Ghorvani R. , Kelley VE , et al: The effect of dietary supplementation with n-3 polyunsaturated fatty acids on the synthesis of interleukin-1 and tumor necrosis factor by mononuclear cells. N Engl J Med 320:265-271, 1989