The 1990 Borden Award Lecture Dietary regulation of fatty acid and triglyceride metabolism

1991 ◽  
Vol 69 (11) ◽  
pp. 1637-1647 ◽  
Author(s):  
Gene R. Herzberg
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipoprotein Lipase ◽  
Fatty Acid Synthesis ◽  
Dietary Fat ◽  
Acid Synthesis ◽  
Fish Oils ◽  
Dietary Fish

The level of circulating triacylglycerols is determined by the balance between their delivery into the plasma and their removal from it. Plasma triacylglycerols are derived either from dietary fat as chylomicrons or from endogenous hepatic synthesis as very low density lipoproteins. Their removal occurs through the action of lipoprotein lipase after which the fatty acids are either stored in adipose tissue or oxidized, primarily in skeletal muscle and heart. The composition of the diet has been shown to influence many of these processes. Hepatic fatty acid synthesis and triacylglycerol secretion are affected by the quantity and composition of dietary fat, carbohydrate, and protein. Polyunsaturated but not saturated fats reduce hepatic fatty acid synthesis by decreasing the amount of the lipogenic enzymes needed for de novo fatty acid synthesis. Dietary fish oils are particularly effective at reducing both fatty acid synthesis and triacylglycerol secretion and as a result are hypotriacylglycerolemic, particularly in hypertriacylglycerolemic individuals. In addition, dietary fish oils can increase the oxidation of fatty acids and lead to increased activity of lipoprotein lipase in skeletal muscle and heart. It appears that the hypotriacylglycerolemic effect of dietary fish oils is mediated by effects on both synthesis and removal of circulating triacylglycerols.Key words: lipid, fish oil, fructose, liver, adipose tissue, oxidation.

Captopril enhanced insulin-stimulated glycogen synthesis in skeletal muscle but not fatty acid synthesis in adipose tissue of hereditary hypertriglyceridemic rats

Metabolism ◽  
2003 ◽  
Vol 52 (11) ◽  
pp. 1406-1412 ◽  
Author(s):  
Monika Cahová ◽  
Hana Vavrinková ◽  
Milada Tutterova ◽  
Elen Meschisvilli ◽  
Ludmila Kazdova
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Glycogen Synthesis ◽  
Acid Synthesis

LIPOGENESIS IN ADIPOSE TISSUE OF MEAL-FED RATS: A POSSIBLE REGULATORY ROLE OF α-GLYCEROPHOSPHATE FORMATION

1967 ◽  
Vol 45 (2) ◽  
pp. 201-214 ◽  
Author(s):  
Gilbert A. Leveille
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Incubation Medium ◽  
Control Mechanism ◽  
Acid Synthesis ◽  
Fatty Acyl ◽  
Epididymal Adipose Tissue ◽  
Malic Dehydrogenase

The incorporation of acetate-1-14C into fatty acids by isolated epididymal adipose tissue of fed and fasted rats adapted to a single daily 2-hour meal (meal eaters) or fed ad libitum (nibblers) was investigated. Fasting (22 hours) markedly depressed lipogenesis whereas fatty acid synthesis increased linearly with time of refeeding in meal-fed but not in nibbling rats. The activities of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and NADP-malic dehydrogenase in adipose tissue of meal-fed or nibbling rats were not altered as a consequence of a 22-hour fast or of subsequent feeding for 2 hours. The incorporation of acetate-1-l4C into fatty acids by adipose tissue of fasted meal-eating or nibbling animals was markedly enhanced by the addition of unlabeled pyruvate or oxaloacetate to the incubation medium. This stimulatory effect was not observed with adipose tissue front fed meal-eating rats. The addition of unlabeled glucose and insulin to the incubation medium markedly enhanced acetate-1-14C incorporation into fatty acids by isolated adipose tissue and completely overcame any effect of fasting. Adipose tissue converted pyruvate-1-14C, -2-14C, or -3-14C to fatty acids and glyceride-glycerol. The results obtained are consistent with the functioning of a pathway in adipose tissue involving mitochondrial carboxylation of pyruvate to oxaloacetate, and equilibration of the newly formed oxaloacetate with malate and fumarate, followed by cytoplasmic conversion of oxaloacetate to phosphoenol pyruvate. The data are interpreted to support a control mechanism in which fatty acid synthesis is inhibited by tissue fatty acids and fatty acyl-CoA derivatives. The inhibition could in turn be reduced by the availability of α-glycerophosphate, for the esterification of fatty acids. This control mechanism is proposed as the explanation for the refeeding response observed in adipose tissue of meal-fed rats.

Effects of pregnancy and ovarian steroids on fatty acid synthesis and uptake in Syrian hamsters

1991 ◽  
Vol 260 (1) ◽  
pp. R153-R158 ◽  
Author(s):  
A. J. Bhatia ◽  
G. N. Wade
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
White Adipose Tissue ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Acid Synthesis ◽  
De Novo Lipogenesis ◽  
Ovarian Steroids ◽  
Syrian Hamsters

The effects of pregnancy and ovarian steroids on the in vivo distribution of newly synthesized fatty acids (incorporation of tritium from 3H2O into fatty acid) in Syrian hamsters (Mesocricetus auratus) were examined. During late, but not early, gestation hamsters had reduced levels of newly synthesized fatty acids in heart, liver, uterus, and white adipose tissues (parametrial and inguinal fat pads). Treatment of ovariectomized hamsters with estradiol + progesterone significantly decreased fatty acid synthesis-uptake in heart, liver, and inguinal white adipose tissue. Treatment with either estradiol or progesterone alone was without significant effect in any tissue. Pretreatment of hamsters with Triton WR-1339 (tyloxapol), an inhibitor of lipoprotein lipase activity and tissue triglyceride uptake, abolished the effects of estradiol + progesterone in white adipose tissue and heart but not in liver. Thus hamsters lose body fat during pregnancy in part because of decreased de novo lipogenesis. The effect of pregnancy on lipogenesis is mimicked by treatment with estradiol + progesterone but not by either hormone alone. Furthermore, it appears that the liver is the principal site of estradiol + progesterone action on lipogenesis in Syrian hamsters.

scholarly journals Utilization of methylmalonate for the synthesis of branched-chain fatty acids by preparations of chicken liver and sheep adipose tissue

1978 ◽  
Vol 176 (3) ◽  
pp. 799-804 ◽  
Author(s):  
J R Scaife ◽  
K W J Wahle ◽  
G A Garton
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Complex Mixture ◽  
Acid Synthesis ◽  
Inhibitory Effect ◽  
Chicken Liver ◽  
Malonyl Coa ◽  
Branched Chain

1. The utilization of methyl[2-14C]malonyl-CoA for fatty acid synthesis was investigated using synthetase preparations from chicken liver and sheep adipose tissue. 2. The rate of fatty acid synthesis from acetyl-CoA and malonyl-CoA was greatly diminished in the presence of methylmalonyl-CoA. 3. In the absence of malonyl-CoA, methylmalonyl-CoA was utilized for fatty acid synthesis only very slowly by the synthetase from sheep adipose tissue and not at all by that from chicken liver. 4. Despite the inhibitory effect of methylmalonyl-CoA on fatty acid synthesis from malonyl-CoA, it was utilized by the synthetase preparations from both species to produce a complex mixture of methyl-branched fatty acids.

The effects of dietary fat on fatty acid synthesis and malic enzyme activity in liver from growing chicks

1969 ◽  
Vol 47 (7) ◽  
pp. 743-746 ◽  
Author(s):  
Alan G. Goodridge
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Dietary Fat ◽  
Malic Enzyme ◽  
Corn Oil ◽  
Acid Synthesis ◽  
Hepatic Lipogenesis ◽  
Malic Enzyme Activity

Hepatic malic enzyme activity and incorporation of glucose-U-14C into fatty acids in liver slices was no greater in birds fed fat-free diets than in those fed the same diets supplemented with corn oil. The results suggest that in the chick, in contrast to the rat, dietary fat does not suppress hepatic lipogenesis.

scholarly journals Fatty acid synthesis in liver and adipose tissue of normal and genetically obese (ob/ob) mice during the 24-hour cycle

1975 ◽  
Vol 150 (2) ◽  
pp. 167-173 ◽  
Author(s):  
D A Hems ◽  
E A Rath ◽  
T R Verrinder
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Dark Period ◽  
Acid Synthesis ◽  
Obese Mice ◽  
Total Rate ◽  
Relative Significance ◽  
Adipose Organ

1. The synthesis of long-chain fatty acids de novo was measured in the liver and in regions of adipose tissue in intact normal and genetically obses mice throughout the daily 24h cycle. 2. The total rate of synthesis, as measured by the rate of incorporation of 3H from 3H2O into fatty acid, was highest during the dark period, in liver and adipose tissue of lean or obese mice. 3. The rate of incorporation of 14C from [U-14C]glucose into fatty acid was also followed (in the same mice). The 14C/3H ratios were higher by a factor of 5-20 in parametrial and scapular fat than that in liver. This difference was less marked during the dark period (of maximum fatty acid synthesis). 4. In normal mice, the total rate of fatty acid synthesis in the liver was about twofold greater than that in all adipose tissue regions combined. 5. In obese mice, the rate of fatty acid synthesis was more rapid than in lean mice, in both liver and adipose tissue. Most of the extra lipogenesis occurred in adipose tissue. The extra hepatic fatty acids synthesized in obese mice were located in triglyceride rather than phospholipid. 6. In adipose tissue of normal mice, the rate of fatty acid synthesis was most rapid in the intra-abdominal areas and in brown fat. In obese mice, all regions exhibited rapid rates of fatty acid synthesis. 7. These results shed light on the relative significance of liver and adipose tissue (i.e. the adipose ‘organ’) in fatty acid synthesis in mice, on the mino importance of glucose in hepatic lipogenesis, and on the alterations in the rate of fatty acid synthesis in genetically obese mice.

Genetic variations in subcutaneous adipose tissue metabolism in sheep

1988 ◽  
Vol 47 (2) ◽  
pp. 263-270 ◽  
Author(s):  
P. A. Sinnett-Smith ◽  
J. A. Woolliams
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipoprotein Lipase ◽  
Fatty Acid Synthesis ◽  
Subcutaneous Adipose Tissue ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Adipocyte Volume ◽  
Glycerol Synthesis ◽  
Subcutaneous Adipose

ABSTRACTAdipocyte volume rates of fatty acid synthesis, acylglycerol glycerol synthesis and lipolysis (basal and noradrenaline stimulated) along with the activities of acetyl CoA carboxylase and lipoprotein lipase were determined in subcutaneous adipose tissue, sampled by biopsy, from the rump of four breeds of sheep differing in growth and body characteristics.Significant differences among breeds were observed for adipocyte volume, fatty acid synthesis, stimulated lipolysis rates, initial and total acetyl CoA carboxylase activity and lipoprotein lipase activity, but not for acylglycerol glycerol synthesis.Differences in adipocyte volume did not appear to be related to the previously reported carcass fatnesses of the breeds. Similarly differences in adipocyte volume were not related to differences in either de novo fatty acid synthesis or lipolysis rates. Across breeds there was a trend toward higher acylglycerol glycerol synthesis rates associated with greater adipocyte volume although the source of fatty acids for esterification varied greatly.Breed variation in fatness in sheep therefore appears to be a consequence of different balances of anabolic and catabolic processes in adipose tissue, with a unique pattern for each breed. Further elucidation of these patterns may lead to the identification of key sites for genetic manipulation. In addition these breed differences provide an alternative, complementary and qualitatively different, model for the study of the control of fat metabolism to that provided by nutritional or hormonal manipulations.

scholarly journals Aspects of adipose-tissue metabolism in foetal lambs

1981 ◽  
Vol 196 (3) ◽  
pp. 819-824 ◽  
Author(s):  
R G Vernon ◽  
J P Robertson ◽  
R A Clegg ◽  
D J Flint
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipoprotein Lipase ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Acetyl Coa ◽  
Perirenal Adipose Tissue ◽  
Glycerol Synthesis

1. The mean volume of adipocytes, the rates of fatty acid and acylglycerol glycerol synthesis from various precursors (in vitro), the rates of oxidation of acetate and glucose (in vitro) and the activities of lipoprotein lipase and various lipogenic enzymes were determined for perirenal adipose tissue from foetal lambs during the last month of gestation. 2. The fall in the rate of growth of perirenal adipose tissue during the last month of gestation is associated with a diminished capacity for fatty acid synthesis and lipoprotein lipase activity, but no change in the rate of acylglycerol glycerol synthesis was observed. There was no fall in the activities of cytosolic acetyl-CoA synthetase or the NADP-linked dehydrogenases, suggesting that the decrease in the rate of fatty acid synthesis was due to an impairment at the level of acetyl-CoA carboxylase or fatty acid synthetase. 3. The rate of fatty acid synthesis from acetate was greater than that from glucose. The rate of fatty acid synthesis from glucose per adipocyte of foetal lambs was similar to that of young sheep. The characteristic metabolism of adipose tissue of the adult sheep is thus present in the foetus, despite the relatively large amounts of glucose in the foetal ‘diet’.

Fatty Acid Synthesis from Pyruvate in White Adipose Tissue: the Effect of Norepinephrine

1971 ◽  
Vol 49 (6) ◽  
pp. 736-741 ◽  
Author(s):  
M. L. Halperin
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Pentose Phosphate ◽  
Epididymal Adipose Tissue ◽  
Phenazine Methosulfate ◽  
Fasted Rats ◽  
Lines Of Evidence

Pyruvate incorporation into fatty acids has been studied in epididymal adipose tissue taken from normal and 24-h-fasted rats. This rate was limited by the rate of cytoplasmic NADPH2 generation as suggested by three lines of evidence.(1) D-Glucose-12C increased pyruvate-U-14C incorporation into fatty acids threefold. This augmentation was independent of L-glycerol 3-phosphate concentrations as the level of this metabolite was not increased. Addition of lactate-U-14C to the pyruvate medium increased the tissue L-glycerol 3-phosphate levels but did not increase the rate of fatty acid synthesis.(2) Phenazine methosulfate (2 μM) inhibited pyruvate or pyruvate plus lactate (L/P = 3/1) conversion to fatty acids whilst stimulating fatty acid synthesis from glucose or lactate alone.(3) Norepinephrine stimulated pyruvate but not glucose or glucose plus pyruvate incorporation into fatty acids. This correlated with norepinephrine-induced glycogenosis and NADPH2 production in the pentose phosphate pathway. This was shown by increased 1-14CO2/6-14CO2 production from endogenously labelled glycogen and the absence of this effect in glycogen-depleted adipocytes (24-h-fasted rats).

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