Effects of the oral hypoglycemic agent methyl palmoxirate on exercise capacity of rats

1984 ◽  
Vol 62 (7) ◽  
pp. 815-818 ◽  
Author(s):  
J. C. Young ◽  
J. E. Bryan ◽  
S. H. Constable ◽  
G. F. Tutwiler ◽  
J. O. Holloszy
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Exercise Capacity ◽  
Liver Glycogen ◽  
Oral Hypoglycemic Agent ◽  
Strenuous Exercise ◽  
Acid Oxidation ◽  
Hypoglycemic Agent ◽  
Minimal Treatment ◽  
Exercise Induced

The effect of the oral hypoglycemic agent methyl palmoxirate (methyl 2-tetradecylglycidate, McN-3716), a selective inhibitor of long chain fatty acid oxidation, on the exercise capacity of normal rats was evaluated. Daily administration of 2.5 mg/kg for 7 days, or of a single dose of 10 mg/kg, of methyl palmoxirate did not affect the ability of rats to perform strenuous exercise of an intensity that caused exhaustion in less than 30 min. The ability to perform prolonged, moderately strenuous exercise of an intensity that could be maintained for more than 60 min was decreased slightly (17%) in the methyl palmoxirate treated rats. This effect appeared to be mediated by a significant reduction in initial liver glycogen content in the methyl palmoxirate treated rats. As a consequence, the methyl palmoxirate treated rats became hypoglycemic during prolonged exercise. Inhibition of fatty acid oxidation in skeletal muscle was minimal. Treatment with methyl palmoxirate protected against the development of exercise-induced ketosis. It appears that the liver is the major site of action of methyl palmoxirate when given in low dosage.

scholarly journals A Low-Carbohydrate Ketogenic Diet and Treadmill Training Enhanced Fatty Acid Oxidation Capacity but Did Not Enhance Maximal Exercise Capacity in Mice

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 611
Author(s):  
Sihui Ma ◽  
Jiao Yang ◽  
Takaki Tominaga ◽  
Chunhong Liu ◽  
Katsuhiko Suzuki
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Exercise Capacity ◽  
Ketogenic Diet ◽  
Maximal Exercise ◽  
Treadmill Running ◽  
Acid Oxidation ◽  
Oxidation Capacity ◽  
Low Carbohydrate ◽  
Maximal Exercise Capacity

The low-carbohydrate ketogenic diet (LCKD) is a dietary approach characterized by the intake of high amounts of fat, a balanced amount of protein, and low carbohydrates, which is insufficient for metabolic demands. Previous studies have shown that an LCKD alone may contribute to fatty acid oxidation capacity, along with endurance. In the present study, we combined a 10-week LCKD with an 8-week forced treadmill running program to determine whether training in conjunction with LCKD enhanced fatty acid oxidation capacity, as well as whether the maximal exercise capacity would be affected by an LCKD or training in a mice model. We found that the lipid pool and fatty acid oxidation capacity were both enhanced following the 10-week LCKD. Further, key fatty acid oxidation related genes were upregulated. In contrast, the 8-week training regimen had no effect on fatty acid and ketone body oxidation. Key genes involved in carbohydrate utilization were downregulated in the LCKD groups. However, the improved fatty acid oxidation capacity did not translate into an enhanced maximal exercise capacity. In summary, while favoring the fatty acid oxidation system, an LCKD, alone or combined with training, had no beneficial effects in our intensive exercise-evaluation model. Therefore, an LCKD may be promising to improve endurance in low- to moderate-intensity exercise, and may not be an optimal choice for those partaking in high-intensity exercise.

Effects of subbasal insulin infusion on resting and exercise-induced glucose turnover in depancreatized dogs

1993 ◽  
Vol 264 (3) ◽  
pp. E334-E341 ◽  
Author(s):  
Z. Q. Shi ◽  
A. Giacca ◽  
K. Yamatani ◽  
S. J. Fisher ◽  
H. L. Lickley ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Insulin Infusion ◽  
Glucose Turnover ◽  
Acid Oxidation ◽  
Minimal Amount ◽  
Adrenergic Blockade ◽  
Metabolic Clearance ◽  
Diabetic Dogs ◽  
Exercise Induced

beta-Adrenergic blockade suppressed lipolysis and normalized the exercise-induced increments in glucose uptake (GlcU) and metabolic clearance rate (MCR) in alloxan-diabetic dogs with residual insulin, but not in insulin-deprived depancreatized dogs even when combined with methylpalmoxirate (MP), which suppresses fatty acid oxidation. The effects of a minimal amount of insulin (as in the alloxan-diabetic dog), were studied in depancreatized, 24-h insulin-deprived dogs during rest and treadmill exercise (6 km/h, 10% slope) using a 1/4 basal insulin infusion (50 microU.kg-1.min-1, insulin, n = 6) alone, or with MP (20 mg.kg-1.day orally, 2.5 days, MP+insulin, n = 6). At rest, insulin decreased circulating fatty acids (31%) and Glc (13%) and increased GlcU and MCR (86 and 72%). Glc production was unaffected. MP plus insulin markedly suppressed hepatic fatty acid oxidation, decreased Glc (44%) and Glc production (50%), and markedly increased MCR (128%). The exercise-induced increments in MCR were markedly improved only by MP plus insulin but were still lower than in the propranolol-treated alloxan-diabetic dogs. Plasma Glc inversely correlated with the exercise-induced increase in MCR (r = -0.86). We conclude that 1) acute infusion of subbasal insulin improved GlcU in depancreatized dogs at rest but not during exercise; 2) inhibition of fatty acid oxidation combined with subbasal insulin improved the exercise-induced increase in MCR; and 3) the difference in GlcU and MCR between the MP plus insulin-treated depancreatized dogs and the beta-blockade-treated alloxan-diabetic dogs suggests a difference between acute and chronic effects of insulin.

Excess body fat in men decreases plasma fatty acid availability and oxidation during endurance exercise

2004 ◽  
Vol 286 (3) ◽  
pp. E354-E362 ◽  
Author(s):  
Bettina Mittendorfer ◽  
David A. Fields ◽  
Samuel Klein
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Body Fat ◽  
Fat Mass ◽  
Total Fatty Acid ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Plasma Fatty Acids ◽  
Exercise Induced

The effect of relative body fat mass on exercise-induced stimulation of lipolysis and fatty acid oxidation was evaluated in 15 untrained men (5 lean, 5 overweight, and 5 obese with body mass indexes of 21 ± 1, 27 ± 1, and 34 ± 1 kg/m2, respectively, and %body fat ranging from 12 to 32%). Palmitate and glycerol kinetics and substrate oxidation were assessed during 90 min of cycling at 50% peak aerobic capacity (V̇o2 peak) by use of stable isotope-labeled tracer infusion and indirect calorimetry. An inverse relationship was found between %body fat and exercise-induced increase in glycerol appearance rate relative to fat mass ( r2 = 0.74; P < 0.01). The increase in total fatty acid uptake during exercise [(μmol/kg fat-free mass) × 90 min] was ∼50% smaller in obese (181 ± 70; P < 0.05) and ∼35% smaller in overweight (230 ± 71; P < 0.05) than in lean (354 ± 34) men. The percentage of total fatty acid oxidation derived from systemic plasma fatty acids decreased with increasing body fat, from 49 ± 3% in lean to 39 ± 4% in obese men ( P < 0.05); conversely, the percentage of nonsystemic fatty acids, presumably derived from intramuscular and possibly plasma triglycerides, increased with increasing body fat ( P < 0.05). We conclude that the lipolytic response to exercise decreases with increasing adiposity. The blunted increase in lipolytic rate in overweight and obese men compared with lean men limits the availability of plasma fatty acids as a fuel during exercise. However, the rate of total fat oxidation was similar in all groups because of a compensatory increase in the oxidation of nonsystemic fatty acids.

scholarly journals A Multi-Ingredient Formula Ameliorates Exercise-Induced Fatigue by Changing Metabolic Pathways and Increasing Antioxidant Capacity in Mice

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3120
Author(s):  
Hui Chen ◽  
Xuan Ma ◽  
Lixing Cao ◽  
Shuang Zhao ◽  
Chong Zhao ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Antioxidant Capacity ◽  
Signaling Pathways ◽  
Glucose Transporter ◽  
Adenosine Monophosphate ◽  
Liver Glycogen ◽  
Acid Oxidation ◽  
Isoleucine Leucine ◽  
Improve Exercise Performance ◽  
Exercise Induced

Multiple mechanisms are involved in exercise-induced fatigue, including energy depletion, metabolite accumulation, and oxidative stress, etc. The mechanistic findings provide a rationale for a multi-targeted approach to exercise-induced fatigue management. This study created a multi-ingredient formula mixed with valine, isoleucine, leucine, β-alanine, creatine, l-carnitine, quercetin, and betaine, based on the functional characteristics of these agents, and evaluated the preventive effect of this mechanism-based formula on exercise-induced fatigue. Results showed that the 7-d formula supplement significantly increased the running duration time of mice by 14% and the distance by 20% in an exhaustive treadmill test, indicating that the formula could delay fatigue appearance and improve exercise performance. Mechanistically, the formula enhanced fatty acid oxidation and spared liver glycogen by regulating the fat/glucose metabolism-related signaling pathways, including phospho-adenosine monophosphate-activated protein kinase α (p-AMPKα), phospho-acetyl CoA carboxylase (p-ACC), carnitine palmitoyl-transferase 1B (CPT1B), fatty acid translocase (CD36), and glucose transporter type 4 (GLUT4), and increased antioxidant capacity. The findings suggested that the formula tested in this study effectively ameliorated exercise-induced fatigue by targeting multi-signaling pathways, showing promise as a regimen to fight exercise-induced fatigue.

Effect of adrenodemedullation on decline in muscle malonyl-CoA during exercise

1993 ◽  
Vol 74 (5) ◽  
pp. 2548-2551 ◽  
Author(s):  
W. W. Winder ◽  
R. W. Braiden ◽  
D. C. Cartmill ◽  
C. A. Hutber ◽  
J. P. Jones
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Treadmill Running ◽  
Acid Oxidation ◽  
Sham Operation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Malonyl Coa ◽  
Exercise Induced ◽  
Rate Limiting

Malonyl-CoA is an inhibitor of carnitine palmitoyltransferase, a rate-limiting enzyme of fatty acid oxidation. Previous studies have indicated that muscle malonyl-CoA declines in rats during treadmill running. This decrease may be important for allowing an increased rate of fatty acid oxidation during prolonged exercise. This study was designed to determine whether epinephrine is essential for inducing the decline in muscle malonyl-CoA during exercise. Male Sprague-Dawley rats underwent adrenodemedullation (ADM) or sham operation. After allowing 3 wk for recovery, rats were killed (pentobarbital anesthesia) at rest or after running at 21 m/min up a 15% grade for 60 min. Red quadriceps malonyl-CoA decreased from 2.6 +/- 0.3 to 0.8 +/- 0.07 nmol/g in sham-operated rats and from 2.2 +/- 0.3 to 0.8 +/- 0.1 nmol/g in ADM rats. White quadriceps malonyl-CoA decreased to similar levels during exercise in both sham-operated and ADM rats. A second experiment on 24-h fasted rats also showed no impairment in the exercise-induced decline in red quadriceps malonyl-CoA as a result of adrenodemedullation. The hormones of the adrenal medulla are therefore unessential for inducing the decline in malonyl-CoA during exercise.

Muscle malonyl-CoA decreases during exercise

1989 ◽  
Vol 67 (6) ◽  
pp. 2230-2233 ◽  
Author(s):  
W. W. Winder ◽  
J. Arogyasami ◽  
R. J. Barton ◽  
I. M. Elayan ◽  
P. R. Vehrs
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Oxidation ◽  
Plasma Catecholamines ◽  
Male Rats ◽  
Acid Oxidation ◽  
Glycogen Depletion ◽  
Carnitine Acyltransferase ◽  
Malonyl Coa ◽  
Important Regulator ◽  
Exercise Induced

Malonyl-CoA, the inhibitor of carnitine acyltransferase I, is an important regulator of fatty acid oxidation and ketogenesis in the liver. Muscle carnitine acyltransferase I has previously been reported to be more sensitive to malonyl-CoA inhibition than is liver carnitine acyltransferase I. Fluctuations in malonyl-CoA concentration may therefore be important in regulating the rate of fatty acid oxidation in muscle during exercise. Male rats were anesthetized (pentobarbital via venous catheters) at rest or after 30 min of treadmill exercise (21 m/min, 15% grade). The gastrocnemius/plantaris muscles were frozen at liquid N2 temperature. Muscle malonyl-CoA decreased from 1.66 +/- 0.17 to 0.60 +/- 0.05 nmol/g during the exercise. This change was accompanied by a 31% increase in cAMP in the muscle. The decline in malonyl-CoA occurred before muscle glycogen depletion and before onset of hypoglycemia. Plasma catecholamines, corticosterone, and free fatty acids were all significantly increased during the exercise. This exercise-induced decrease in malonyl-CoA may be important for allowing the increase in muscle fatty acid oxidation during exercise.

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