scholarly journals Effects of insulin treatment of diabetic rats on hepatic partitioning of fatty acids between oxidation and esterification, phospholipid and acylglycerol synthesis, and on the fractional rate of secretion of triacylglycerol in vivo

1994 ◽  
Vol 304 (1) ◽  
pp. 177-182 ◽  
Author(s):  
A M B Moir ◽  
V A Zammit

1. The hypothesis that insulin treatment of streptozotocin-diabetic rats does not alter acutely the ability of acylcarnitine synthesis to compete successfully for cytosolic long-chain acyl-CoA [Grantham and Zammit (1988) Biochem. J. 249, 409-414], was tested in vivo by using the technique of selective labelling of hepatic fatty acids in awake unrestrained rats. In the same animals, the partitioning of hepatic fatty acids between acylglycerol and phospholipid synthesis, and of newly labelled triacylglycerol between secretion into the plasma and retention in the liver, was also studied. 2. In untreated diabetic animals, the ratio of fatty acid oxidation to esterification was double that found in normal fed animals, whereas there were no differences in the values of the above-mentioned parameters of glycerolipid metabolism. Thus the insulin status of the rats only has chronic effects on specific aspects of fatty acid metabolism in the liver. 3. Treatment of diabetic rats with insulin resulted in no change in the oxidation/esterification ratio for the first 5 h after the start of insulin administration. Thereafter, there were reciprocal changes in the 14CO2 expired (an index of oxidation) and 14C label recovered in hepatic and plasma glycerolipids. However, the pattern of partitioning observed in normal fed rats was still not re-established after 8 h of insulin treatment. 4. There was a small and transient decrease in the fractional rate of triacylglycerol secretion by the liver at the start of insulin treatment and an increase in the proportion of labelled fatty acid that was utilized for phospholipid synthesis such that phospholipid labelling as a proportion of that of total glycerolipids was doubled after 8 h of insulin treatment. 5. The data are discussed in relation to the roles of insulin in mediating acute changes in hepatic fatty acid metabolism and very-low-density-lipoprotein triacylglycerol secretion by the liver.

1984 ◽  
Vol 247 (3) ◽  
pp. H387-H394 ◽  
Author(s):  
A. J. Liedtke ◽  
S. H. Nellis ◽  
O. D. Mjos

Fatty acids in excess impair mechanical function and electrical stability in ischemic hearts. The purpose of the present studies was to test whether oxfenicine, an agent capable of reducing fatty acid metabolism, can prevent these consequences and in so doing improve hemodynamic performance. Two groups of working swine hearts (n = 15), extracorporeally perfused with whole blood, were compared over 90 min of controlled coronary perfusion. An emulsion of triacylglycerols (Intralipid) with heparin were administered systemically to augment serum fatty acids threefold (0.30 to 0.92 mumol/ml). Labeled [U14C]palmitate was administered selectively into the left anterior descending coronary circulation to follow fatty acid oxidation. Coronary flow in this bed was decreased by 50% over the final 30 min of perfusion. Saline (n = 7) or oxfenicine (17-33 mg/kg, n = 8) was administered to placebo or treated animals at 30 min perfusion. 14CO2 production from labeled palmitate was decreased by 55% (P less than 0.025) at normal flows in oxfenicine-treated hearts and was reduced further during ischemia. Tissue levels of acyl carnitine were significantly reduced and acetyl CoA levels significantly increased in oxfenicine-treated hearts both in aerobic and ischemic myocardium. These changes were associated with an improvement in mechanical function. Left ventricular systolic and developed pressures and maximum left ventricular dP/dt were increased by 36 delta %, P less than 0.01; 46 delta %, P less than 0.025; and 41 delta %, P less than 0.025, respectively, at end ischemia as compared with placebo hearts.(ABSTRACT TRUNCATED AT 250 WORDS)


2009 ◽  
Vol 34 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Gregory R. Steinberg

During moderate-intensity exercise, fatty acids are the predominant substrate for working skeletal muscle. The release of fatty acids from adipose tissue stores, combined with the ability of skeletal muscle to actively fine tune the gradient between fatty acid and carbohydrate metabolism, depending on substrate availability and energetic demands, requires a coordinated system of metabolic control. Over the past decade, since the discovery that AMP-activated protein kinase (AMPK) was increased in accordance with exercise intensity, there has been significant interest in the proposed role of this ancient stress-sensing kinase as a critical integrative switch controlling metabolic responses during exercise. In this review, studies examining the role of AMPK as a regulator of fatty acid metabolism in both adipose tissue and skeletal muscle during exercise will be discussed. Exercise induces activation of AMPK in adipocytes and regulates triglyceride hydrolysis and esterfication through phosphorylation of hormone sensitive lipase (HSL) and glycerol-3-phosphate acyl-transferase, respectively. In skeletal muscle, exercise-induced activation of AMPK is associated with increases in fatty acid uptake, phosphorylation of HSL, and increased fatty acid oxidation, which is thought to occur via the acetyl-CoA carboxylase-malony-CoA-CPT-1 signalling axis. Despite the importance of AMPK in regulating fatty acid metabolism under resting conditions, recent evidence from transgenic models of AMPK deficiency suggest that alternative signalling pathways may also be important for the control of fatty acid metabolism during exercise.


2020 ◽  
Vol 19 (2) ◽  
pp. 154
Author(s):  
Djeyne Silveira Wagmacker ◽  
Alice Miranda De Oliveira ◽  
Edna Conceição De Oliveira ◽  
Alan Carlos Nery Dos Santos ◽  
Luiz Erlon Araújo Rodrigues ◽  
...  

Introduction: Diet is a complex set of exposures that frequently interact, and whose cumulative effects influence the results of health. This includes effects on systemic inflammation markers in metabolic disturbances and cardiovascular diseases. Various studies have been presented relating the effect of physical exercise on lipids, however, the results are still controversial. Objective: To describe fatty acid metabolism and the effect of physical exercise on secondary complications. Methods: An integrative review was conducted on topics in the Medline, Pubmed, Web of Science and Scopus databases, published up to the year 2017. Results: Fatty acids, depending on their biochemical characteristics and spatial configuration, have differentiated effect on cardiovascular health, however, studies still present contradictory results about the therapeutic use of certain fatty acids. Physical exercise appears to benefit fatty acid metabolism and attenuate the complications secondary to the intake of certain fatty acids, and potentializes the positive effects of distinct fatty acids. Conclusion: However, variants of physical exercise, such as intensity, duration, time of observation of effects of the results, limit the authors to concluding, with a certain degree of certainty, about the effect of physical exercise on fatty acids and secondary complications, since the studies in the literature continue to be contradictory.Keywords: fatty acids, exercise, inflammation, oxidative stress.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Catharina M. C. Mels ◽  
Peet Jansen van Rensburg ◽  
Francois H. van der Westhuizen ◽  
Pieter J. Pretorius ◽  
Elardus Erasmus

Acetylsalicylic acid and/or its metabolites are implicated to have various effects on metabolism and, especially, on mitochondrial function. These effects include both inhibitory and stimulatory effects. We investigated the effect of both combined and separate oral acetylsalicylic acid and acetaminophen administration at therapeutic doses on the urinary metabolite profile of human subjects. In this paper, we provided in vivo evidence, in human subjects, of a statistically significant increase in isobutyrylcarnitine after the administration of a therapeutic dose of acetylsalicylic acid. We, therefore, propose an inhibitory effect of acetylsalicylic acid on the short-chain fatty acid metabolism, possibly at the level of isobutyryl-CoA dehydrogenase.


Sign in / Sign up

Export Citation Format

Share Document