Fatty acid uptake in normal human myocardium

Journal Article · Sun Sep 01 04:00:00 EDT 1991 · Circulation Research (An Official Journal of the American Heart Association); (United States)

DOI:https://doi.org/10.1161/01.RES.69.3.857· OSTI ID:5228784

Vyska, K; Meyer, W; Stremmel, W; Notohamiprodjo, G; Minami, K; Machulla, H J; Gleichmann, U; Meyer, H; Koerfer, R ^[1]

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1. University of Bochum (West Germany)

Fatty acid binding protein has been found in rat aortic endothelial cell membrane. It has been identified to be a 40-kDa protein that corresponds to a 40-kDa fatty acid binding protein with high affinity for a variety of long chain fatty acids isolated from rat heart myocytes. It is proposed that this endothelial membrane fatty acid binding protein might mediate the myocardial uptake of fatty acids. For evaluation of this hypothesis in vivo, influx kinetics of tracer-labeled fatty acids was examined in 15 normal subjects by scintigraphic techniques. Variation of the plasma fatty acid concentration and plasma perfusion rate has been achieved by modulation of nutrition state and exercise conditions. The clinical results suggest that the myocardial fatty acid influx rate is saturable by increasing fatty acid plasma concentration as well as by increasing plasma flow. For analysis of these data, functional relations describing fatty acid transport from plasma into myocardial tissue in the presence and absence of an unstirred layer were developed. The fitting of these relations to experimental data indicate that the free fatty acid influx into myocardial tissue reveals the criteria of a reaction on a capillary surface in the vicinity of flowing plasma but not of a reaction in extravascular space or in an unstirred layer and that the fatty acid influx into normal myocardium is a saturable process that is characterized by the quantity corresponding to the Michaelis-Menten constant, Km, and the maximal velocity, Vmax, 0.24 {plus minus} 0.024 mumol/g and 0.37 {plus minus} 0.013 mumol/g(g.min), respectively. These data are compatible with a nondiffusional uptake process mediated by the initial interaction of fatty acids with the 40-kDa membrane fatty acid binding protein of cardiac endothelial cells.

• OSTI ID: 5228784
• Journal Information: Circulation Research (An Official Journal of the American Heart Association); (United States), Journal Name: Circulation Research (An Official Journal of the American Heart Association); (United States) Vol. 69:3; ISSN CIRUA; ISSN 0009-7330
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMAL TISSUES
ANIMALS
AORTA
ARTERIES
BIOSYNTHESIS
BLOOD VESSELS
BODY
CARBOXYLIC ACIDS
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CELL MEMBRANES
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
DYNAMIC FUNCTION STUDIES
ENDOTHELIUM
EXERCISE
HEART
ISOTOPES
MAMMALS
MAN
MEMBRANES
METABOLISM
MUSCLES
MYOCARDIUM
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PRIMATES
PROTEINS
RADIOISOTOPE SCANNING
SCINTISCANNING
SYNTHESIS
THALLIUM ISOTOPES
TISSUES
VERTEBRATES