scholarly journals Pyruvate Dehydrogenase Activity in the Liver, Brain and Adipose-Tissue of Lipid-Deprived Developing Rats. Effect of Minute Amounts of Polyunsaturated Fatty Acids

1982 ◽  
Vol 9 (2) ◽  
pp. 221-229 ◽  
Author(s):  
C. Loriette ◽  
M. Launay ◽  
D. Lapous ◽  
J. Raulin
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Pyruvate Dehydrogenase ◽  
Tetraenoic Acid ◽  
Female Progeny ◽  
Adipose Tissues ◽  
Minute Amount ◽  
Acid Ratio ◽  
The Brain ◽  
Stimulation Of

ABSTRACT:The present experiment was carried out using the following diets:FF, fat-free, andLPthe same diet with 0.7% sunflower oil - given to the progeny of females kept on theFFdiet since the mating. After 10 mM Mg2+ activation of the PDH phosphatase, the rate of [1-14C] pyruvate decarboxylation into acetyl-CoA ester units was determined in the liver, brain and adipose-tissue of the pair-fed developing rats.Results: In the male progeny, pyruvate dehydrogenase (PDH) activity was higher (61%) in theLPgroup livers than in theFFgroup livers, at the end of the 13 week experiment. Such a difference was not observed in the two group brains up to the 91 days postweaning, but was even larger (94%) between adipose-tissues of theLPandFFgroups. In the female progeny kept 12 weeks on the diets, PDH activity in theLPgroup tissues was also higher than in theFFgroup tissues: 63% in the liver, 43% in adipose-tissues, and less than 10% in the brain. Therefore, a minute amount of lipids high in linoleic acid appeared to increase PDH activity, and especially in the liver and adipose-tissues of animals kept on a strictly fat-free diet. This stimulation of the PDH activity seems closely related to the phospholipid rehabilitation in the tissues (decrease in the trienoic: tetraenoic acid ratio values).

FREE FATTY ACID METABOLISM IN CHINESE HAMSTERS

1966 ◽  
Vol 44 (1) ◽  
pp. 47-57 ◽  
Author(s):  
James Campbell ◽  
G. R. Green
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Spontaneous Diabetes ◽  
Chinese Hamster ◽  
Diabetic Rats ◽  
Epididymal Adipose Tissue ◽  
Time Interval ◽  
Adipose Tissues ◽  
Chinese Hamsters

In normal Chinese hamsters (Cricetulus griseus) the mean concentration of free fatty acids (FFA) in serum varied from group to group, but was (i) consistently 4 to 9 times greater than in rats, dogs, or man; (ii) slightly higher than in Syrian hamsters; (iii) two- to four-fold higher than in fasting or alloxan-diabetic rats. The epididymal adipose tissue of the Chinese hamster (i) had initial concentrations of FFA comparable to those in the rat and Syrian hamster; (ii) released, in the same time interval, 8- to 10-fold more FFA in vitro than this tissue of the rat; (iii) had higher concentrations of FFA after incubation than the incubated tissue of the rat. The retroperitoneal (perirenal) adipose tissue of the Chinese hamster was less active in release of fatty acids in vitro than the epididymal, but was, however, more active than the epididymal adipose tissue of the rat. These characteristics of FFA metabolism in the Chinese hamster were apparently attributable to species, not to age, diet, or sex. In the Chinese hamster, the weight of the epididymal adipose tissue per gram of body was relatively high. It appears that in this species the rate of release of fatty acids from adipose tissue is great, leading to high FFA concentrations in serum.In Chinese hamster and rat adipose tissues in vitro, glucose and insulin (separately) reduced the rate of release of FFA and the amount of FFA in the tissues, but glucose and insulin together produced the greatest reductions. The net reduction in FFA release by glucose and insulin in vitro was greater in tissue from the Chinese hamster. Insulin markedly increased glucose uptake by the adipose tissues of both species. The possible relation of the results to spontaneous diabetes in the Chinese hamster is discussed.

Control of Fatty Acid Synthesis in White Adipose Tissue by Insulin: Coordination Between the Mitochondrial Citrate Transporter and Pyruvate Dehydrogenase

1974 ◽  
Vol 52 (10) ◽  
pp. 813-821 ◽  
Author(s):  
Carol M. Schiller ◽  
Wayne M. Taylor ◽  
Mitchell L. Halperin
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Pyruvate Dehydrogenase ◽  
Active Form ◽  
Acid Synthesis ◽  
Citrate Transporter ◽  
Maximal Activation ◽  
Initial Decrease ◽  
Preincubation Medium

The transport of citrate out of adipose tissue mitochondria is inhibited by palmitoyl-CoA. This inhibition varied inversely with the concentration of extramitochondrial exchanging anion.When adipose tissue is incubated in vitro, the rate of citrate output into the medium was increased by the addition of insulin. The tissue citrate content did not change significantly. Norepinephrine caused an initial decrease in the rate of citrate output (2.5 min). The tissue citrate content was approximately twofold higher at this time.When rats were fasted for 36 h, less than 40% of adipose tissue pyruvate dehydrogenase was in the active form. Optimal interconversion to the active form was achieved by preincubation with 4 mM Mg2+ in the absence of added Ca2+ (endogenous Ca2+ was approximately 25 μM). Citrate addition to the preincubation medium decreased this activation of pyruvate dehydrogenase. The inhibition induced by citrate correlated best with the concentration of 'free' citrate when the 'free' Mg2+ concentration was sufficient to cause near-maximal activation of pyruvate dehydrogenase.A hypothesis regarding the coordination of regulation of pyruvate conversion to fatty acids is formulated based on these findings.

scholarly journals Fatty acid profiles in adipose tissues and liver differ between horses and ponies

2018 ◽  
Author(s):  
Stephanie Adolph ◽  
Carola Schedlbauer ◽  
Dominique Blaue ◽  
Axel Schöniger ◽  
Claudia Gittel ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Liver Tissue ◽  
Lipid Extraction ◽  
Lipid Classes ◽  
Adipose Tissues ◽  
Health And Disease

AbstractFatty acids, as key components of cellular membranes and complex lipids, may play a central role in endocrine signalling and the function of adipose tissue and liver. Thus, the lipid fatty acid composition may play a role in health and disease status in the equine. This study aimed to investigate the fatty acid composition of different tissues and liver lipid classes by comparing Warmblood horses and Shetland ponies under defined conditions. We hypothesized that ponies show different lipid patterns than horses in adipose tissue, liver and plasma. Six Warmblood horses and six Shetland ponies were housed and fed under identical conditions. Tissue and blood sampling were performed following a standardized protocol. A one-step lipid extraction, methylation and trans-esterification method with subsequent gas chromatography was used to analyse the total lipid content and fatty acid profile of retroperitoneal, mesocolon and subcutaneous adipose tissue, liver and plasma. In the adipose tissues, saturated fatty acids (SFAs) and n-9 monounsaturated fatty acids (n-9 MUFAs) were most present in ponies and horses. N-6 polyunsaturated fatty acids (n-6 PUFAs), followed by SFAs, were most frequently found in liver tissue and plasma in all animals. Horses, in comparison to ponies, had significantly higher n-6 PUFA levels in all tissues and plasma. In liver tissue, horses had significantly lower hepatic iso-branched-chain fatty acids (iso-BCFAs) than ponies. The hepatic fatty acid composition of selected lipid classes was different between horses and ponies. In the polar PL fraction, horses had low n-9 MUFA and n-3 PUFA contents but higher n-6 PUFA contents than ponies. Furthermore, iso-BCFAs are absent in several hepatic lipid fractions of horses but not ponies. The differences in fatty acid lipid classes between horses and ponies provide key information on the species- and location-specific regulation of FA metabolism, thus affecting health and disease risk.

scholarly journals Neuropathy and neural plasticity in the subcutaneous white adipose depot

2018 ◽  
Author(s):  
Magdalena Blaszkiewicz ◽  
Jake W. Willows ◽  
Amanda L. Dubois ◽  
Stephen Waible ◽  
Cory P. Johnson ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Neural Plasticity ◽  
Neurotrophic Factor ◽  
Metabolic Diseases ◽  
Metabolic Health ◽  
The Body ◽  
Adipose Tissues ◽  
Adipose Organ ◽  
Tissue Aging ◽  
The Brain

AbstractThe difficulty in obtaining as well as maintaining weight loss, together with the loss of metabolic control in conditions like diabetes and cardiovascular disease, may represent pathological situations of inadequate neural communication between the brain and peripheral organs and tissues. Innervation of adipose tissues by peripheral nerves provides a means of communication between the master metabolic regulator in the brain (chiefly the hypothalamus), and energy-expending and energy-storing cells in the body (primarily adipocytes). Although chemical and surgical denervation studies have clearly demonstrated how crucial adipose tissue neural innervation is for maintaining proper metabolic health, we have uncovered that adipose tissue becomes neuropathic in various conditions of metabolic dysregulation. Here, utilizing both human and mouse adipose tissues, we present evidence of adipose tissue neuropathy, or loss of innervation, under pathophysiological conditions such as obesity, diabetes, and aging, all of which are concomitant with insult to the adipose organ and metabolic dysfunction. Neuropathy is indicated by loss of nerve fiber protein expression, reduction in synaptic markers, and less neurotrophic factor expression in adipose tissue. Aging-related adipose neuropathy particularly results in loss of innervation around the tissue vasculature. These findings underscore that peripheral neuropathy is not restricted to classic tissues like the skin of distal extremities, and that loss of innervation to adipose may trigger or exacerbate metabolic diseases. In addition, we have demonstrated stimulation of adipose tissue neural plasticity with exercise, cold exposure or neurotrophic factor treatment, which may ameliorate adipose neuropathy and be a potential therapeutic option to re-innervate adipose and restore metabolic health.

Does hyperinsulinemia in ob/ob mice cause an insulin-stimulated adipose tissue?

1976 ◽  
Vol 230 (3) ◽  
pp. 602-607 ◽  
Author(s):  
EG Loten ◽  
Y Le Marchand ◽  
F Assimacopoulos-Jeannet ◽  
RM Denton ◽  
B Jeanrenaud
Keyword(s):  
Adipose Tissue ◽  
Glucose Metabolism ◽  
Pyruvate Dehydrogenase ◽  
Serum Insulin ◽  
Acetyl Coa Carboxylase ◽  
Obese Mice ◽  
Lipogenic Enzymes ◽  
Insulin Stimulation ◽  
Endogenous Insulin ◽  
Stimulation Of

After a 1-h preincubation to remove endogenous insulin, adipose tissue of obese mice (C57BL/L4 ob/ob) had a lower rate of glucose metabolism than tissue which was not preincubated. In contrast, preincubation did not change the metabolism of adipose tissue from lean mice (C57B1/6J +/+). The preincubation effect was abolished in obese mice which had had their serum insulin levels lowered toward normal by streptozotocin treatment. Injection of anti-insulin serum to obese mice caused adipose tissue removed 15 min after the injection to display a rate of glucose metabolsim lower than that of tissue removed before the injection. No such effect was seen in lean mice. These data are consistent with the hypothesis that hyperinsulinemia in the obese mice causes a chronic state of insulin stimulation of their adipose tissue, possibly contributing to their high rates of lipogenesis and their obesity. Several lipogenic enzymes were measured in adipose tissue of both lean and obese mice, and no single enzymatic abnormality was detected which might explain the hyperlipogenesis. Pyruvate dehydrogenase and acetyl-CoA carboxylase were both insulin-sensitive enzymes in lean and obese mice.

Effect of norepinephrine and uncoupling agents on brown adipose tissue

1968 ◽  
Vol 46 (6) ◽  
pp. 897-902 ◽  
Author(s):  
Barbara A. Horwitz ◽  
Paul A. Herd ◽  
Robert Emrie Smith
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Brown Fat ◽  
Brown Adipose ◽  
In Vitro Response ◽  
Stimulation Of ◽  
Thermogenic Response

Examination of the in vivo effect of 2,4-dinitrophenol (DNP) on the brown adipose tissue of cold-exposed rats, as well as the in vitro response of this tissue to DNP and dicumarol, indicates that brown fat does possess a functional electron transport coupled phosphorylating system. Moreover, the fact that a norepinephrine-induced thermogenic response (in vivo) can be elicited from the brown fat after DNP administration implies that the effect of norepinephrine (NE) is not primarily due either to a physiological uncoupling by fatty acids, the level of which is increased by NE, or to stimulation of an ATP-ase system. Alternatively, our data suggest that under basal conditions (i.e. when the animal is not stimulated by cold stress or NE), the heat production (oxygen consumption) of the brown fat is limited by the availability of substrate rather than ADP. It is thus proposed that the thermogenic effect of NE results from the stimulation of lipolysis and an attendant increase of substrate available for oxidation.

scholarly journals Lipid synthesis in vivo by tissues of the maternal and foetal guinea pig

1976 ◽  
Vol 154 (1) ◽  
pp. 159-161 ◽  
Author(s):  
C T Jones ◽  
W Firmin
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Guinea Pig ◽  
Lipid Synthesis ◽  
Short Chain Fatty Acids ◽  
Adipose Tissues ◽  
Pig Liver ◽  
Foetal Liver ◽  
Guinea Pig Liver

The rate of lipid biosynthesis in vivo was determined in pregnant guinea pigs after maternal and foetal injections of 3H2O. Synthesis in the maternal tissues was low and in the foetal liver and adipose tissues relatively high. In the foetal liver it reached a peak at about two-thirds of gestation, whereas that in the foetal adipose tissue occurred later. These results were used to support the view that lipid synthesis in the foetal guinea-pig liver at two-thirds of gestation is largely from short-chain fatty acids, whereas in foetal adipose tissue glucose is probably the major substrate.

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