Conditions for oxygen and substrate transport in muscles in exercising mammals

1991 ◽  
Vol 160 (1) ◽  
pp. 263-283 ◽  
Author(s):  
H. Hoppeler ◽  
R. Billeter
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Work Conditions ◽  
High Energy ◽  
Fatty Acid Transport ◽  
Facilitated Diffusion ◽  
High Energy Phosphates ◽  
Lactate Shuttle ◽  
Fatty Acid Binding ◽  
Intracellular Location

The structural conditions relevant for metabolite exchange in anaerobic and aerobic work conditions in muscle tissue are reviewed. High-intensity non-steady-state exercise is supported by the phosphocreatine pool, which serves as a shuttle for high-energy phosphates produced by glycolysis and by aerobic metabolism. This is achieved through the intermediary of a topologically organized creatine kinase isozyme system. The muscle capillary network supplies substrate and environmental oxygen to the mitochondria. The network is quantitatively matched to the muscle oxidative capacity, determined structurally by mitochondrial volume. Capillary hematocrit, erythrocyte spacing and oxygen saturation of myoglobin are critical variables for oxygen release from microvessels. Myoglobin greatly helps intracellular oxygen transfer as, under aerobic work conditions, it keeps intracellular oxygen tension low and uniform in the muscle fibers. During sustained submaximal work, muscle cells are fueled by both endogenous (triglycerides and glycogen) and circulatory (lactate, glucose and fatty acids) substrates. A lactate shuttle in which lactate may move through the circulation, as well as directly from fiber to fiber, provides many of the carbohydrate-derived carbon skeletons for terminal oxidation. Glucose is taken up from the interstitial space by facilitated diffusion, mostly mediated by a glucose transporter (GLUT4) that is translocated from an intracellular location to the sarcolemma by activity and insulin. Extramyocellular transport of fatty acids is mediated by albumin, while fatty-acid-binding proteins are held responsible for intracellular fatty acid transport.

scholarly journals Omega-3 fatty acids transport through the placenta

2016 ◽  
Vol 2 (1) ◽  
pp. 1-8
Author(s):  
Ariful Islam ◽  
Takanori Kodama ◽  
Yui Yamamoto ◽  
Majid Ebrahimi ◽  
Hirofumi Miyazaki ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Placental Transfer ◽  
Fatty Acid Binding Proteins ◽  
Fatty Acid Transport ◽  
Omega 3 ◽  
Fatty Acid Binding ◽  
Membrane Bound ◽  
Fatty Acid Transport Proteins

The placenta is a temporary vital organ for sustaining the development of the fetus throughout gestation. Although the fatty acid composition delivered to the fetus is largely determined by maternal circulating levels, the placenta preferentially transfers physiologically important long-chain polyunsaturated fatty acids (LC-PUFAs), particularly omega-3 (n-3) FAs. The precise mechanisms governing these transfers were covered in a veil, but have started to be revealed gradually. Several evidences suggest fatty acid transport proteins (FATPs), placental specific membrane bound fatty acid binding proteins (pFABPpm) and fatty acid translocases (FAT/CD36) involved in LC-PUFAs uptake. Our studies have shown that the placental transfer of omega-3 FAs through the trophoblast cells is largely contributed by fatty acid binding protein 3 (FABP3). Recently there are considerable interests in the potential for dietary omega-3 FAs as a therapeutic intervention for fetal disorders. In fact, prenatal supply of omega-3 FAs is essential for brain and retinal development. Recent findings suggest a potential opportunity of omega-3 FA interventions to decrease the incidence of type 2 diabetes in future generations. In this review, we discuss the molecular mechanism of transportation of omega-3 FAs through the placenta and how omega-3 FAs deficiency/supplementation impact on fetal development.Asian J. Med. Biol. Res. March 2016, 2(1): 1-8

Stopped-flow kinetic analysis of long-chain fatty acid dissociation from bovine serum albumin

2002 ◽  
Vol 363 (3) ◽  
pp. 809-815 ◽  
Author(s):  
Erland J.F. DEMANT ◽  
Gary V. RICHIERI ◽  
Alan M. KLEINFELD
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Time Course ◽  
Acid Dissociation ◽  
Fatty Acid Transport ◽  
Acid Transport ◽  
Fatty Acid Binding ◽  
Kinetics Of ◽  
Initial Fatty Acid ◽  
Long Chain

The kinetics of the interaction of long-chain fatty acids (referred to as fatty acids) with albumin is critical to understanding the role of albumin in fatty acid transport. In this study we have determined the kinetics of fatty acid dissociation from BSA and the BSA-related fatty acid probe BSA-HCA (BSA labelled with 7-hydroxycoumarin-4-acetic acid) by stopped-flow methods. Fatty acid—albumin complexes of a range of natural fatty acid types and albumin molecules (donors) were mixed with three fatty acid-binding acceptor proteins. Dissociation of fatty acids from the donor was monitored by either the time course of donor fluorescence/absorbance or the time course of acceptor fluorescence. The results of these measurements indicate that fatty acid dissociation from BSA as well as BSA-HCA is well described by a single exponential function over the entire range of fatty acid/albumin molar ratios used in these measurements, from 0.5:1 to 6:1. The observed rate constants (kobs) for the dissociation of each fatty acid type reveal little or no dependence on the initial fatty acid/albumin ratio. However, dissociation rates were dependent upon the type of fatty acid. In the case of native BSA with an initial fatty acid/BSA molar ratio of 3:1, the order of kobs values was stearic acid (1.5s−1)<oleic acid<palmitic acid≅linoleic acid<arachidonic acid (8s−1) at 37°C. The corresponding values for BSA-HCA were about half the values for BSA. The results of this study show that the rate of fatty acid dissociation from native BSA is more than 10-fold faster than reported previously and that the off-rate constants for the five primary fatty acid-binding sites differ by less than a factor of 2. We conclude that for reported rates of fatty acid transport across cell membranes, dissociation of fatty acids from the fatty acid—BSA complexes used in the transport studies should not be rate-limiting.

Fatty acid binding protein in heart and skeletal muscles of the migratory barnacle goose throughout development

1999 ◽  
Vol 276 (3) ◽  
pp. R637-R643 ◽  
Author(s):  
Maurice M. A. L. Pelsers ◽  
Patrick J. Butler ◽  
Charles M. Bishop ◽  
Jan F. C. Glatz
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Binding Protein ◽  
Muscle Protein ◽  
Binding Protein ◽  
Fatty Acid Transport ◽  
Long Distance ◽  
Barnacle Goose ◽  
Fatty Acid Binding ◽  
Acid Binding Protein

The long-distance migratory flights of birds are predominantly fueled by the oxidation of fatty acids, which are sourced primarily from extracellular adipose stores. These fatty acids have to be transported, via the circulatory system, to the mitochondria of the active muscles. An important facilitator of fatty acid transport within the cytoplasm of muscle cells is fatty acid binding protein (FABP), which serves as an intracellular carrier of long-chain fatty acids. In mammals, the muscular FABP content is related to the fatty acid oxidation capacity of the tissue. The aim of this study was to measure FABP in samples taken from the cardiac, pectoralis, and semimembranosus muscles of a long-distance avian migrant, the barnacle goose ( Branta leucopsis), at various stages of development. Western blot analysis identified a single goose muscle protein of 15 kDa that was able to bind fatty acids and showed a 66% cross-reactivity with antibodies against human heart-type FABP. Captive goslings showed no significant changes in FABP content of either the heart (62.6 ± 10.6 μg/g wet wt) or the semimembranosus muscle (8.4 ± 1.9 μg/g wet wt) during development. However, in both peripheral and deep sites within the pectoralis muscle, FABP content of samples taken from captive goslings were ∼10-fold higher throughout development and reached values of 30–40 μg/g wet wt in fledging goslings at 7 wk of age. A further twofold higher value was seen in wild but not in captive goslings immediately before migration (12 wk of age). Similarly, FABP content was significantly higher in pectoralis samples taken from wild adults (94.3 ± 3.6 μg/g wet wt) compared with those from captive adults (60.5 ± 3.6 μg/g wet wt). These results suggest that the experience of flight activity may be of critical importance in achieving maximal expression of FABP in the pectoralis muscles of postfledging and mature geese immediately before migration.

scholarly journals Placental transfer of long-chain polyunsaturated fatty acids (LC-PUFA)

2007 ◽  
Vol 35 (s1) ◽  
pp. S5-S11 ◽  
Author(s):  
Berthold Koletzko ◽  
Elvira Larqué ◽  
Hans Demmelmair
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Human Placenta ◽  
Placental Transfer ◽  
Fetal Brain ◽  
Fatty Acid Transport ◽  
Omega 3 ◽  
Fatty Acid Binding ◽  
Long Chain

AbstractConsiderable evidence exists for marked beneficial effects of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) during pregnancy. The omega-3 LC-PUFA docosahexaenoic acid (DHA) is incorporated in large amounts in fetal brain and other tissues during the second half of pregnancy, and several studies have provided evidence for a link between early DHA status of the mother and visual and cognitive development of her child after birth. Moreover, the supplementation of omega-3 LC-PUFA during pregnancy increases slightly infant size at birth, and significantly reduces early preterm birth before 34 weeks of gestation by 31%. In our studies using stable isotope methodology in vivo, we demonstrated active and preferential materno-fetal transfer of DHA across the human placenta and found the expression of human placental fatty acid binding and transport proteins. From the correlation of DHA values with placental fatty acid transport protein 4 (FATP 4), we conclude that this protein is of key importance in mediating DHA transport across the human placenta. Given the great importance of placental DHA transport for infant outcome, further studies are needed to fully appreciate the effects and optimal strategies of omega-3 fatty acid interventions in pregnancy, dose response relationships, and the potential differences between subgroups of subjects such as women with gestational diabetes or other gestational pathology. Such studies should contribute to optimize substrate intake during pregnancy and lactation that may improve pregnancy outcome as well as fetal growth and development.

Transfer of fatty acids between intracellular membranes: roles of soluble binding proteins, distance, and time

2002 ◽  
Vol 282 (1) ◽  
pp. G105-G115 ◽  
Author(s):  
R. A. Weisiger ◽  
S. D. Zucker
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Binding Proteins ◽  
Specific Cell ◽  
Fatty Acid Transport ◽  
Membrane Separations ◽  
Acid Transport ◽  
Fatty Acid Binding ◽  
Intracellular Membranes ◽  
Rate Limiting

Soluble fatty acid binding proteins (FABPs) are thought to facilitate exchange of fatty acids between intracellular membranes. Although many FABP variants have been described, they fall into two general classes. “Membrane-active” FABPs exchange fatty acids with membranes during transient collisions with the membrane surface, whereas “membrane-inactive” FABPs do not. We used modeling of fatty acid transport between two planar membranes to examine the hypothesis that these two classes catalyze different steps in intracellular fatty acid transport. In the absence of FABP, the steady-state flux of fatty acid from the donor to the acceptor membrane depends on membrane separation distance (d) approaching a maximum value ( J max) as d approaches zero. J max is one-half the rate of dissociation of fatty acid from the donor membrane, indicating that newly dissociated fatty acid has a 50% chance of successfully reaching the acceptor membrane before rebinding to the donor membrane. For larger membrane separations, successful transfer becomes less likely as diffusional concentration gradients develop. The mean diffusional excursion of the fatty acid into the water phase (dm) defines this transition. For d≪dm, dissociation from the membrane is rate limiting, whereas for d≫dm, aqueous diffusion is rate limiting. All forms of FABP increase dmby reducing the rate of rebinding to the donor membrane, thus maintaining J max over larger membrane separations. Membrane-active FABPs further increase J max by catalyzing the rate of dissociation of fatty acids from the donor membrane, although frequent membrane interactions would be expected to reduce their diffusional mobility through a membrane-rich cytoplasm. Individual FABPs may have evolved to match the membrane separations and densities found in specific cell lines.

scholarly journals Lipid Accumulation and Chronic Kidney Disease

Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 722 ◽  
Author(s):  
Zhibo Gai ◽  
Tianqi Wang ◽  
Michele Visentin ◽  
Gerd Kullak-Ublick ◽  
Xianjun Fu ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Kidney Disease ◽  
Lipid Accumulation ◽  
Scavenger Receptor ◽  
Fatty Acid Uptake ◽  
Lipid Lowering ◽  
Fatty Acid Transport ◽  
Acid Uptake

Obesity and hyperlipidemia are the most prevalent independent risk factors of chronic kidney disease (CKD), suggesting that lipid accumulation in the renal parenchyma is detrimental to renal function. Non-esterified fatty acids (also known as free fatty acids, FFA) are especially harmful to the kidneys. A concerted, increased FFA uptake due to high fat diets, overexpression of fatty acid uptake systems such as the CD36 scavenger receptor and the fatty acid transport proteins, and a reduced β-oxidation rate underlie the intracellular lipid accumulation in non-adipose tissues. FFAs in excess can damage podocytes, proximal tubular epithelial cells and the tubulointerstitial tissue through various mechanisms, in particular by boosting the production of reactive oxygen species (ROS) and lipid peroxidation, promoting mitochondrial damage and tissue inflammation, which result in glomerular and tubular lesions. Not all lipids are bad for the kidneys: polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to help lag the progression of chronic kidney disease (CKD). Lifestyle interventions, especially dietary adjustments, and lipid-lowering drugs can contribute to improve the clinical outcome of patients with CKD.

scholarly journals A novel acyl-CoA-binding protein from bovine liver. Effect on fatty acid synthesis

1987 ◽  
Vol 241 (1) ◽  
pp. 189-192 ◽  
Author(s):  
I B Mogensen ◽  
H Schulenberg ◽  
H O Hansen ◽  
F Spener ◽  
J Knudsen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Binding Protein ◽  
Fatty Acid Synthetase ◽  
Bovine Liver ◽  
Acid Synthesis ◽  
Fatty Acid Binding Proteins ◽  
Fatty Acid Binding ◽  
Medium Chain ◽  
Chain Acyl

Bovine liver was shown to contain a hitherto undescribed medium-chain acyl-CoA-binding protein. The protein co-purifies with fatty-acid-binding proteins, but was, unlike these proteins, unable to bind fatty acids. The protein induced synthesis of medium-chain acyl-CoA esters on incubation with goat mammary-gland fatty acid synthetase. The possible function of the protein is discussed.

scholarly journals Up-regulation of the expression of the gene for liver fatty acid-binding protein by long-chain fatty acids

1996 ◽  
Vol 319 (2) ◽  
pp. 483-487 ◽  
Author(s):  
Claire MEUNIER-DURMORT ◽  
Hélène POIRIER ◽  
Isabelle NIOT ◽  
Claude FOREST ◽  
Philippe BESNARD
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Binding Protein ◽  
Fold Increase ◽  
Long Chain Fatty Acids ◽  
Liver Fatty Acid ◽  
Fatty Acid Binding ◽  
Acid Binding Protein ◽  
Fabp Gene ◽  
Long Chain

The role of fatty acids in the expression of the gene for liver fatty acid-binding protein (L-FABP) was investigated in the well-differentiated FAO rat hepatoma cell line. Cells were maintained in serum-free medium containing 40 µM BSA/320 µM oleate. Western blot analysis showed that oleate triggered an approx. 4-fold increase in the cytosolic L-FABP level in 16 h. Oleate specifically stimulated L-FABP mRNA in time-dependent and dose-dependent manners with a maximum 7-fold increase at 16 h in FAO cells. Preincubation of FAO cells with cycloheximide prevented the oleate-mediated induction of L-FABP mRNA, showing that protein synthesis was required for the action of fatty acids. Run-on transcription assays demonstrated that the control of L-FABP gene expression by oleate was, at least in part, transcriptional. Palmitic acid, oleic acid, linoleic acid, linolenic acid and arachidonic acid were similarly potent whereas octanoic acid was inefficient. This regulation was also found in normal hepatocytes. Therefore long-chain fatty acids are strong inducers of L-FABP gene expression. FAO cells constitute a useful tool for studying the underlying mechanism of fatty acid action.

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