Free fatty acids enhance the oxidation of oxymyoglobin and inhibit the peroxidase activity of metmyoglobin

1990 ◽  
Vol 68 (9) ◽  
pp. 1096-1102 ◽  
Author(s):  
John M. Stewart
Keyword(s):  
Fatty Acid ◽  
Sodium Oleate ◽  
Peroxidase Activity ◽  
Reaction System ◽  
Long Chain Fatty Acid ◽  
Oxidation Rates ◽  
Low Concentrations ◽  
Fatty Acid Peroxidation

The effect of low concentrations of sodium oleate on the oxidation of oxymyoglobin to metmyoglobin has been examined. This long chain fatty acid results in a tripling of the initial rate (1.5–4.3 h−1) at which oxymyoglobin is converted to metmyoglobin and more than doubling of the rate of the long-term reaction (0.12–0.33 h−1). Examination of rate constant enhancement over a range of oleate concentrations (0–0.215 mM) has allowed an estimate of association constants for both phases of the reaction system. The peroxidase activity expressed by metmyoglobin towards hydrogen peroxide is inhibited by the presence of sodium oleate by a fivefold increase in the apparent Km value (0.33–1.77 mM). The observed changes in oxymyoglobin concentration over time are discussed in terms of competition between metmyoglobin, which acts as a peroxidase decreasing in situ concentrations of H2O2, and oxymyoglobin, which also is oxidized by the peroxide. It is shown that oleate can bind to metmyoglobin and azidometmyoglobin, but not oxymyoglobin. Catalase reduces the oxidation rates of oxymyoglobin in the presence or in the absence of oleate, substantiating the involvement of H2O2. The results are discussed in relation to the potential increase in tissue peroxidations in the presence of ischaemically elevated fatty acid concentrations.Key words: myoglobin, fatty acid, peroxidation, autoxidation, peroxidase.

scholarly journals Long-term Experience with Triheptanoin in 12 Austrian Patients with Long-chain Fatty Acid Oxidation Disorders

2020 ◽  
Author(s):  
Thomas Zöggeler ◽  
Katharina Stock ◽  
Monika Jörg-Streller ◽  
Johannes Spenger ◽  
Vassiliki Konstantopoulou ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Pediatric Patients ◽  
Chain Fatty Acid ◽  
Acid Oxidation ◽  
Long Chain Fatty Acid ◽  
Fatty Acid Oxidation Disorders ◽  
One Year ◽  
The One ◽  
Long Term Experience

Abstract BackgroundLong-chain fatty acid oxidation disorders (LC-FAOD) are a group of rare inborn errors of metabolism with autosomal recessive inheritance that may cause life-threatening events. Treatment with triheptanoin, a synthetic seven-carbon fatty acid triglyceride compound with an anaplerotic effect, seems beneficial, but clinical experience is limited. We report our long-term experience in an Austrian cohort of LC-FAOD patients.MethodsWe retrospectively assessed clinical outcome and total hospitalization days per year before and after start with triheptanoin by reviewing medical records of 12 Austrian LC-FAOD patientsResultsFor 12 Austrian LC-FAOD patients at three metabolic centers, triheptanoin was started shortly after birth in 3/12, and between 7.34 and 353.3 (median 44.5; mean 81.1) months of age in 9/12 patients. For 11 pediatric patients, mean duration of triheptanoin intake was 5.3 (median 3.9, range 1.2 to 15.7) years, 10/11 pediatric patients have an ongoing intake of triheptanoin. One patient quit therapy due to reported side effects. Total hospitalization days per year compared to before triheptanoin treatment decreased by 82.3% from 27.1 (range 11-65) days per year to 4.8 (range 0-13) days per year, and hospitalization days in the one year pre- compared to the one year post-triheptanoin decreased by 69.8% from 27.1 (range 4-75) days to 8.2 (range 0-25) days. All patients are in good clinical condition, show normal psychomotor development and no impairment in daily life activities.ConclusionIn this retrospective observational study in an Austrian LC-FAOD cohort, triheptanoin data show improvement in disease course. Triheptanoin appears to be a safe and beneficial treatment option in LC-FAOD. For further clarification, additional prospective randomized controlled trials are needed.

High-Fat Diet Elevates Liver Docosahexaenoic Acid Possibly through Over-Expression of Very Long-Chain Fatty Acid Elongase 2 in C57BL/6J Mice

2019 ◽  
Vol 89 (1-2) ◽  
pp. 62-72
Author(s):  
Mooli Raja Gopal Reddy ◽  
Gundluri Venkata Asha ◽  
Sravan Kumar Manchiryala ◽  
Uday Kumar Putcha ◽  
Ayyalasomayajula Vajreswari ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
High Fat Diet ◽  
Chain Fatty Acid ◽  
High Fat ◽  
Long Chain Fatty Acid ◽  
Fatty Acid Elongase ◽  
Over Expression ◽  
Long Chain

Abstract. The liver is the main site of lipid metabolism and vitamin A storage. Dietary factors are known to affect liver function, thereby leading to metabolic abnormalities. Here, we assessed the impact of long-term feeding of a high-fat diet on hepatic vitamin A status and lipid metabolism. For this purpose, 14 male and 14 female 35-day-old mice (strain C57BL/6J) were each divided into 2 groups of 7 animals and fed either a stock diet or a high-fat (HF) diet for 26 weeks. In addition to increased body weight/weight gain, the HF diet induced hypertriglyceridemia in both (p < 0.01). However, liver triglyceride levels were comparable among groups, which could be partly explained by unaltered expression of various lipogenic pathway proteins such as sterol regulatory element binding protein 1 (SREBP1), fatty acid synthase (FAS), microsomal triglyceride transfer protein (MTTP), and glycerol 3-phosphate acyl transferase (GPAT). On the other hand, hepatic retinol stores increased significantly in both sexes, whereas males displayed elevated circulatory retinol levels. Notably, long-term feeding of a HF diet elevated n-3 polyunsaturated fatty acid (PUFA) and docosahexaenoic acid (DHA, C22:6) levels in the liver (p ≤ 0.001), which is in line with the over-expression of very long-chain fatty acid elongase 2 (ELOVL2) protein in both sexes of mice (p < 0.01). In conclusion, very long-term feeding of a HF diet increased hepatic retinol stores and induced hypertriglyceridemia. However, it had no effect on hepatic triglyceride accumulation, possibly due to increased DHA levels arising from the ELOVL2-mediated elongation pathway.

Viability of the isolated soleus muscle during long-term incubation

2006 ◽  
Vol 31 (4) ◽  
pp. 467-476 ◽  
Author(s):  
Hakam Alkhateeb ◽  
Adrian Chabowski ◽  
Arend Bonen
Keyword(s):  
Fatty Acid ◽  
Protein Expression ◽  
Glucose Transport ◽  
Fatty Acid Metabolism ◽  
Soleus Muscle ◽  
Glucose Transporter ◽  
Acid Metabolism ◽  
Insulin Signalling ◽  
Low Concentrations

Skeletal muscle metabolism has been examined in perfused hindlimb muscles and in isolated muscle preparations. While long-term viability of the fast-twitch epitrochlearis has been documented with respect to glucose transport, it appears that long-term incubated soleus muscles are less stable when incubated ex vivo for many hours. Therefore, in the present study, we have examined whether the isolated soleus muscle remains metabolically viable for up to 18 h with respect to maintaining ATP and phosphocreatine (PCr) concentrations, carbohydrate and fatty-acid metabolism, insulin signalling, and protein expression. Soleus muscles were incubated in well-oxygenated Medium 199 (M199) supplemented with low concentrations of insulin (14.3 µU/mL) for 0, 6, 12, and 18 h. During this incubating period the concentrations of ATP and PCr were stable, indicating that oxygenation and substrate supply were being maintained. In addition, the concentrations of proglycogen and macroglycogen were not altered, whereas an increase (+30%) in intramuscular triacylglycerol concentration was observed at the end of 18 h of incubation (p < 0.05). Complex molecular processes in the long-term incubated muscles were also stable. This was shown by maintenance of basal as well as insulin-stimulated rates of 3-O-methyl glucose transport, and by the maintenance of protein expression of the glucose transporter GLUT4 and the fatty acid transporters FAT/CD36 and FABPpm. In addition, the insulin-stimulated translocation of GLUT4 to the plasma membrane, which involves a complex signalling cascade, was fully preserved. In conclusion, in well-oxygenated soleus muscles maintained in M199 supplemented with extremely low concentrations of insulin, ATP and PCr concentrations, carbohydrate and fatty acid metabolism, insulin signalling, and protein expression were stably maintained for up to 18 h. This provides for opportunities to examine muscle metabolic function under very highly controlled conditions.

scholarly journals A novel fluorescent long-chain fatty acid-substituted dye: labeling and biodegrading ofMicrothrix parvicella

RSC Advances ◽  
2018 ◽  
Vol 8 (62) ◽  
pp. 35855-35862
Author(s):  
Yingchun Gu ◽  
Dayong Lin ◽  
Xuening Fei ◽  
Cuihong Wang ◽  
Qi Yang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fluorescent Probe ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acid ◽  
Long Chain ◽  
Dye Labeling

M. parvicella in situcould be biodegraded by a novel fluorescent probe of carbazole modified by LCFA(FP1).

scholarly journals In Situ Transesterification of Spirulina Microalgae to Produce Biodiesel Using Microwave Irradiation

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Alex K. Koech ◽  
Anil Kumar ◽  
Zachary O. Siagi
Keyword(s):  
Fatty Acid ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Spirulina Platensis ◽  
Reaction System ◽  
Conventional Heating ◽  
Process Conditions ◽  
In Situ Transesterification ◽  
Algae Biomass

The present technology of transesterification of vegetable oils to produce biodiesel, which is suited to replace petrodiesel, has economic challenges, and therefore, alternative sources are being explored. Microalgae, a renewable, third-generation biofuel resource, have the potential to become a viable feedstock due to their high oil content and environmentally friendly nature. The present study investigates the effect of microwave irradiation on the simultaneous extraction and transesterification of algae lipids to produce fatty acid methyl ester (FAME), in a batch reaction system using sulphuric acid catalyst. In situ transesterification combines the two steps of lipid extraction and transesterification into a single step. The microwave synthesis unit comprised of a 3-neck round bottom flask inside a 1300-Watt microwave oven, fitted with a quick-fit condenser and having an external stirrer. Response surface methodology (RSM) was used to analyse the influence of process variables, dry algae to methanol ratio 1 : 4 − 1 : 14   g / ml , algae biomass to catalyst ratio 1 : 0.0032 − 1 : 0.0368   wt % , and reaction time 1 − 11   min , at 500  rpm stirring rate for in situ reaction. FAME was analysed using gas chromatography (GC). The total lipid content of Arthrospira Spirulina platensis microalgae biomass was found to be 10.7 % by weight. The algae biomass also contained proteins at   51.83 % , moisture content at 7.8 % , and ash content 14.30 % by weight. RSM gave the optimum process conditions as dry algae biomass feed to methanol wt / vol ratio of 1 : 9, catalyst concentration of 2   wt % , and reaction time of   7   minutes   for a maximum FAME yield of 83.43   wt % . The major fatty acid composition of FAME was palmitic 43.83 % , linoleic   38.83 % , and linolenic 19.41 % . FAME properties obtained according to European Standards (EN 14214) and American Society for Testing and Materials (ASTM D 6751) standards were as follows: flash point 16 4 o C calorific value 32,911   kJ / kg , acid value 0.475 KOH / g , viscosity 4.45   m m 2 / s , and specific gravity   0.868 . The study showed that Arthrospira Spirulina platensis microalgae lipid FAME met the biodiesel standards (EN 14214 and ASTM D 6751) and has the potential to replace petrodiesel. Microwave irradiation increased the reaction rate resulting in a reduced reaction time of 7 minutes (as compared to 8 hours for conventional heating) and therefore was found to be a superior heating mode as compared to conventional heating.

Ammonia and Nitrate Uptake in the Lower Great Lakes

1980 ◽  
Vol 37 (9) ◽  
pp. 1365-1372 ◽  
Author(s):  
T. P. Murphy
Keyword(s):  
Great Lakes ◽  
Nitrate Uptake ◽  
Nutrient Concentrations ◽  
Short Term ◽  
Low Concentrations ◽  
Uptake Rates ◽  
Low K ◽  
Slow Turnover

Uptake of NH4+ is consistent with Michaelis–Menten kinetics in the Lower Great Lakes only if one assumes that the indophenol method of measuring NH4+ overestimates the in situ concentration. Short-term incubations were found necessary to avoid induction of nitrate uptake or changes in the rates of NH4+ uptake that occurred in long-term incubations. Uptake rates of nitrate are slow most of the summer. Since the nitrate is also present in low concentrations, most of the summer regeneration of nitrate must be very slow. The slow turnover of particulate N, low nutrient concentrations, slow rate of uptake relative to their ability to take up nitrogen, and the high affinity for ammonia (low Kt) suggest that in summer the primary productivity of the Lower Great Lakes is restricted by nitrogen deficiency.Key words: ammonia, nitrate, Lower Great Lakes

LIPID PEROXIDATION IN DEVELOPING RAT BRAIN

1961 ◽  
Vol 39 (8) ◽  
pp. 1231-1238 ◽  
Author(s):  
E. T. Pritchard ◽  
H. Singh
Keyword(s):  
Lipid Peroxidation ◽  
Fatty Acid ◽  
Rat Brain ◽  
Polyunsaturated Fatty Acid ◽  
Thiobarbituric Acid ◽  
Adult Brain ◽  
Fatty Acid Peroxidation ◽  
Developing Rat ◽  
The Brain

The experimental results indicate that the production of thiobarbituric acid (TBA) positive material, apparently derived for the most part from polyunsaturated fatty acid peroxidation, decreases with maturation of rat brain. It appears that during maturation some factor or process is gradually introduced into, or generated within, the brain which retards the tendency of unsaturates to undergo oxidation in situ. This process is possibly related to the maintenance of stability in adult brain.

Regulation of plasma long-chain fatty acid oxidation in relation to uptake in human skeletal muscle during exercise

2004 ◽  
Vol 287 (4) ◽  
pp. E696-E705 ◽  
Author(s):  
Carsten Roepstorff ◽  
Bodil Vistisen ◽  
Kirstine Roepstorff ◽  
Bente Kiens
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acid ◽  
Human Skeletal Muscle ◽  
Fat Oxidation ◽  
Lipid Binding ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acid ◽  
Oxidation Rates ◽  
Lcfa Uptake ◽  
Long Chain

In the present study, we investigated possible sites of regulation of long-chain fatty acid (LCFA) oxidation in contracting human skeletal muscle. Leg plasma LCFA kinetics were determined in eight healthy men during bicycling (60 min, 65% peak oxygen uptake) with either high (H-FOX) or low (L-FOX) leg fat oxidation (H-FOX: 1,098 ± 140; L-FOX: 494 ± 84 μmol FA/min, P < 0.001), which was achieved by manipulating preexercise muscle glycogen (H-FOX: 197 ± 21; L-FOX: 504 ± 25 mmol/kg dry wt, P < 0.001). Several blood metabolites and hormones were kept nearly similar between trials by allocating a preexercise meal and infusing glucose intravenously during exercise. During exercise, leg plasma LCFA fractional extraction was identical between trials (H-FOX: 17.8 ± 1.6; L-FOX: 18.2 ± 1.8%, not significant), suggesting similar LCFA transport capacity in muscle. On the contrary, leg plasma LCFA oxidation was 99% higher in H-FOX than in L-FOX (421 ± 47 vs. 212 ± 37 μmol/min, P < 0.001). Probably due to the slightly higher ( P < 0.01) plasma LCFA concentration in H-FOX than in L-FOX, leg plasma LCFA uptake was nonsignificantly ( P = 0.17) higher (25%) in H-FOX than in L-FOX, yet the fraction of plasma LCFA uptake oxidized was 61% higher ( P < 0.05) in H-FOX than in L-FOX. Accordingly, the muscle content of several lipid-binding proteins did not differ significantly between trials, although fatty acid translocase/CD36 and caveolin-1 were elevated ( P < 0.05) by the high-intensity exercise and dietary manipulation allocated on the day before the experimental trial. The present data suggest that, in contracting human skeletal muscle with different fat oxidation rates achieved by manipulating preexercise glycogen content, transsarcolemmal transport is not limiting plasma LCFA oxidation. Rather, the latter seems to be limited by intracellular regulatory mechanisms.

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