Diet-induced variation in acetate metabolism of ovine perirenal adipose tissue in vitro

1995 ◽  
Vol 125 (3) ◽  
pp. 429-436 ◽  
Author(s):  
N. D. Scollan ◽  
N. S. Jessop
Keyword(s):  
Adipose Tissue ◽  
Insulin Level ◽  
Metabolizable Energy ◽  
Acetate Metabolism ◽  
Acetate Incorporation ◽  
Acetate Oxidation ◽  
Plasma Parameters ◽  
Carbohydrate Source ◽  
Frequent Feeding

SUMMARYSixteen Blackface wether lambs (25–27 kg) were fed for 9 weeks on diets based on either barley (B) or sugarbeet pulp (S), with either a low or high protein content. A constant amount of metabolizable energy (ME) was given at twice maintenance level. At one stage the animals were fed frequently and blood was sampled over a 24 h period. Plasma was assayed for acetate, glucose and insulin. After slaughter, the metabolism of acetate to CO2 and lipid was investigated in perirenal adipocytes in vitro.Frequent feeding helped to achieve near-steady-state conditions. Carbohydrate source influenced plasma acetate (P < 0·08) but not glucose or insulin. Level of protein in the diet influenced plasma acetate, higher concentrations of acetate were associated with lower levels of protein (P < 0·01). Acetate oxidation and incorporation into lipid was influenced by the concentrations of acetate, glucose and insulin in the incubation media (P < 0·001). Acetate oxidation was influenced by carbohydrate source (P < 0·05), whereas level of protein in the diet affected acetate incorporation into lipid (P < 0·05).These results show how the balance of nutrients provided to a ruminant for metabolism may influence selected plasma parameters and the metabolism of acetate by adipose tissue, which may help to explain the reduced efficiency of ME utilization from more fibrous diets.

Effect of cold stress on lipogenesis by adipose tissue

1960 ◽  
Vol 198 (5) ◽  
pp. 1123-1125 ◽  
Author(s):  
E. J. Masoro ◽  
Edith Porter ◽  
Judith Patkin
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Cold Stress ◽  
Incubation Medium ◽  
Acetate Metabolism ◽  
Hepatic Lipogenesis ◽  
Acetate Oxidation ◽  
Fat Pad ◽  
Striking Finding ◽  
Epididymal Fat

The effect of cold stress on acetate metabolism by adipose tissue was investigated. Cold stress did not affect the ability of the epididymal fat pad to oxidize acetate-1-C14 to C14O2. The addition of unlabeled glucose to the incubation medium did not influence the rate of acetate oxidation in the case of adipose tissue obtained from either control or cold-stressed rats. In the absence of unlabeled glucose, more fatty acids from acetate-1-C14 were synthesized by the adipose tissue from control rats than by that from cold-stressed rats, although very little was synthesized by either. The addition of unlabeled glucose to the incubation medium at the physiologic concentration of 100 mg % caused the adipose tissue from both normal and cold-stressed rats to form fatty acids at high rates. It is a striking finding that cold stress, which almost abolishes hepatic lipogenesis, does not appreciably alter adipose tissue lipogenesis.

MEAL-EATING AND LIPOGENESIS IN VITRO OF RATS FED A LOW-PROTEIN DIET

1964 ◽  
Vol 42 (5) ◽  
pp. 665-670 ◽  
Author(s):  
J. R. Beaton ◽  
V. Feleki ◽  
A. J. Szlavko ◽  
J. A. F. Stevenson
Keyword(s):  
Adipose Tissue ◽  
Food Intake ◽  
Body Weight Gain ◽  
Liver Glycogen ◽  
Male Rats ◽  
Acetate Incorporation ◽  
Casein Diet ◽  
Low Protein ◽  
Daily Food

The response of male rats to the restriction of food intake to 2 hours each day for 14 to 16 days has been assessed by the measurement of food intakes, body weights, liver glycogen concentrations, and lipogenesis of adipose tissue (C14-acetate incorporation in vitro). The animals were fed either a 20% casein diet (controls) or an isocaloric 5% casein diet. As a consequence of meal-eating, and regardless of dietary protein level, the average daily food intake and body weight gain were decreased whereas the lipogenesis in vitro and liver glycogen concentration were increased in comparison with rats fed ad libitum,which is in agreement with earlier findings using normal diets. These observations suggest that the decreased body fat of rats fed a 5% casein diet is not a consequence of an impaired ability of adipose tissue to synthesize fat.

EFFECTS OF FREQUENCY OF FEEDING ON ENERGY METABOLISM AND BODY COMPOSITION OF YOUNG PIGS

1973 ◽  
Vol 53 (1) ◽  
pp. 157-164 ◽  
Author(s):  
V. D. SHARMA ◽  
L. G. YOUNG ◽  
R. G. BROWN ◽  
J. BUCHANAN-SMITH ◽  
G. C. SMITH
Keyword(s):  
Body Composition ◽  
Adipose Tissue ◽  
The Body ◽  
Metabolizable Energy ◽  
Dietary Energy ◽  
Feeding Experiment ◽  
Feeding Frequency ◽  
Young Pigs ◽  
Energy Inputs ◽  
Frequent Feeding

The influence of frequency of feeding on the coefficient of digestibility and metabolizability of dietary energy, fasting heat production, maintenance energy requirements, efficiency of utilization of metabolizable energy (ME) for maintenance and growth, net energy value of diet, rate of lipogenesis in adipose tissue, and the body composition of young pigs was investigated. A total of 40 pigs was used in this study, of which four constituted the initial slaughter group. The remaining 36 pigs were allotted to a feeding experiment of a randomized complete-block design involving a 3 × 2 factorial arrangement (level of dietary energy inputs: 140, 240, and 340 kcal ME/W0.75kg daily; and feeding frequency: two and five times daily). One metabolism experiment was conducted during the 3rd wk of the 37-day feeding experiment. Subcutaneous adipose tissue slices taken immediately after electrocution of 24 pigs were used to determine the rate of lipogenesis as indicated by the metabolism of glucose-U-14C. Frequency of feeding had no effect on the digestible energy, ME, and NEm value of the diet or the efficiency of utilization of ME for maintenance. However, frequent feeding increased the fasting heat production, metabolizable energy requirement for maintenance, net efficiency of utilization of metabolizable energy for production and the NEg value of the diet. Frequency of feeding did not produce any change in the weights of empty stomach or small intestine. Although the rate of lipogenesis in the adipose tissue was not affected by feeding frequency, lipogenesis was increased by an increase in the level of dietary energy inputs. Feeding frequency did not influence the body composition and energy concentration in the empty body of pigs fed 240 and 340 kcal ME/W0.75kg but frequent feeding increased percent water and reduced percent fat in pigs fed 140 kcal ME/W0.75kg daily. Several of the latter pigs were in negative energy balance.

In Vitro Metabolism of Fatty Acids by Adipose and Liver Tissue of the Adrenalectomized Rat

1957 ◽  
Vol 189 (3) ◽  
pp. 433-436 ◽  
Author(s):  
W. F. Perry ◽  
Helen F. Bowen
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Octanoic Acid ◽  
Normal Liver ◽  
Liver Slice ◽  
Acetate Incorporation ◽  
Slice Preparation ◽  
Progressive Loss ◽  
Liver Slices

The utilization of acetate and octanoate by adipose tissue from rats 1 and 2 weeks postadrenalectomy has been studied. In addition, acetate incorporation into liver fatty acids and ketogenesis by liver slices from 2-week postoperative animals has been measured. Adrenalectomy resulted in a progressive loss of fat from adipose tissue. At 1-week postadrenalectomy the incorporation of acetate into fatty acids by adipose tissue did not differ from the control preparations but was much increased 2 weeks after adrenalectomy. At this time there was no increase in utilization of added octanoic acid by the adipose tissue and neither at 1 nor at 2 weeks was the production of CO2 from either acetate or octanoic significantly different from normal. Liver slices from 2-week adrenalectomized animals had a markedly defective ability to incorporate acetate into liver fatty acids similar to that previously noted in 1-week animals. However, liver slice preparation from 2-week adrenalectomized rats showed increased ketone body formation, indicating increased fatty acid utilization by the liver. It is suggested that there is a gradual mobilization of fat from the depots to the liver in the adrenalectomized rat with increased utilization of fat by the liver.

THE EFFECT OF INSULIN ON THE UTILIZATION OF [U-14C]GLUCOSE AND [1-14C]ACETATE BY GOAT ADIPOSE TISSUE IN VITRO

1969 ◽  
Vol 44 (1) ◽  
pp. 115-119 ◽  
Author(s):  
J. ŠKARDA ◽  
S. BARTOŠ
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Glucose Oxidation ◽  
Marked Effect ◽  
Acetate Incorporation ◽  
Adipose Tissue In Vitro ◽  
High Concentrations

SUMMARY No change in the rate of 14CO2 production from [U-14C]glucose by the adipose tissue of goats was found in vitro, even in the presence of high concentrations of insulin (1 and 10 m-u./ml.) when glucose was the only substrate in the medium. However, it was demonstrated that in the presence of acetate as little as 10 μu. insulin/ml. exerted a marked effect on glucose oxidation. The most significant effect of insulin was that on the rate of [1-14C]acetate incorporation into fatty acids in the presence of glucose. These findings support the suggestion that the significance of insulin in ruminants is best demonstrated by its effects on the rate of utilization of acetate in the presence of glucose by adipose tissue.

ACETATE UTILIZATION BY LIVER AND ADIPOSE TISSUE OF RATS FASTED IN THE COLD

1958 ◽  
Vol 36 (1) ◽  
pp. 237-241
Author(s):  
William F. Perry
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Liver Tissue ◽  
Carbon Dioxide Production ◽  
Acetate Incorporation ◽  
Fasted Rats ◽  
Glucose Supplementation

The in vitro incorporation of 1-C14 and 2-C14 acetate into fatty acids and carbon dioxide by liver and adipose tissue was studied in rats fasted at 5 °C. for 24 hours. Compared with fed rats at room temperature, there was a marked decrease in the incorporation of the acetate carbons into fatty acids and carbon dioxide by liver tissue. A pronounced decrease in acetate incorporation into fatty acid was also noted with adipose tissue from these same animals, but only a slight decrease in incorporation into carbon dioxide. Addition of glucose to the incubation medium caused increases in fatty acid formation by liver and adipose tissue from both normal and fasted animals, but glucose supplementation, while increasing the incorporation of acetate into carbon dioxide by liver tissue from cold fasted rats, did not affect carbon dioxide production by liver tissue from normal animals. Incorporation of acetate into carbon dioxide by adipose tissue was unaffected by glucose supplementation with tissue from both normal and cold fasted rats.

Effects of Acipimox, a Nicotinic Acid Derivative, on Lipolysis in Human Adipose Tissue and on Cholesterol Synthesis in Human Jejunal Mucosa

1985 ◽  
Vol 68 (1) ◽  
pp. 83-88 ◽  
Author(s):  
C. Stirling ◽  
M. McAleer ◽  
J. P. D. Reckless ◽  
R. R. Campbell ◽  
D. Mundy ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Cholesterol Synthesis ◽  
Density Lipoprotein ◽  
Human Adipose Tissue ◽  
Jejunal Mucosa ◽  
Acetate Incorporation ◽  
Precursor Pool

1. The mode of action of acipimox (5-methyl-pyrazine carboxylic acid 4-oxide), an hypotriglyceridaemic agent, was examined in human adipose tissue and intestinal mucosa. 2. The rates of release of fatty acids and glycerol from human adipose tissue were measured in vitro. The release of fatty acids and glycerol from adipose tissue maximally stimulated by isoprenaline (10−5 mol/l) fell by 40 and 25% respectively (P<0.025 and P<0.025) in the presence of acipimox (10−5 mol/l). In submaximally stimulated adipose tissue (isoprenaline 10−7 mol/l) acipimox (10−4 mol/l) fully inhibited release of fatty acids (P<0.05) and glycerol (P<0.025) to basal rates. In unstimulated adipose tissue acipimox (10−3 mol/l) reduced the rate of glycerol release (P<0.05), but not the rate of fatty acid release. 3. Cholesterol synthesis in jejunal mucosa was measured in vitro by the incorporation of [2-14C]-acetate into sterols. Addition of cholesterol to the incubation reduced [2-14C]acetate incorporation into sterols from 8.7 ± 2.1 (mean ± standard error) to 3.7 ± 1.0 pmol h−1 mg−1 of tissue (P<0.01). Acipimox at 10−4-10−2 mmol/l had no consistent effect on cholesterol synthesis. 4. Acipimox appears to exert its main hypolipidaemic effect by reducing lipolysis and free fatty acid flux to the liver, thereby reducing the precursor pool size of very low density lipoprotein (VLDL)-triglyceride and VLDL synthesis.

scholarly journals The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep

1986 ◽  
Vol 56 (3) ◽  
pp. 607-614 ◽  
Author(s):  
T. N. Barry ◽  
T. F. Allsop ◽  
Carolyn Redekopp
Keyword(s):  
Adipose Tissue ◽  
Condensed Tannins ◽  
Trifolium Pratense ◽  
Plasma Concentrations ◽  
Acetate Incorporation ◽  
Glycerol Release ◽  
Lotus Pedunculatus ◽  
High Concentrations

1. Three experiments were conducted using Lotus pedunculatus containing high concentrations of condensed tannins (CT), and utilizing the principle that polyethylene glycol (PEG) application (molecular weight 3350) will irreversibly bind a portion of the CT and thus reduce the dietary reactive (i.e. non-PEG bound) CT concentration. Lotus diets containing 95, 45 and 14 g total reactive CT/kg dry matter (DM), induced by spraying with three PEG rates, were given to sheep at hourly intervals (600 g DM/d) for 21 d (Expt 1). In Expts 2 and 3, lambs grazed areas oversown with either lotus (89 g CT/kg DM) or clovers (Trifolium repens and Trifolium pratense; < 1 g CT/kg DM) for 42 and 92 d respectively. In Expt 2 half the animals grazing each forage received oral PEG (75 g/d), whilst in Expt 3 half the lambs were sired by rams selected respectively for low or high levels of sub- cutaneous fat deposition.2. Hormone concentrations in plasma (Expt 1 only) were determined by radioimmunoassay. Rates of [U-14C]-acetate and D-[U-14C]glucose incorporation and oxidation by subcutaneous and abdominal adipose tissue removed at slaughter, together with rate of glycerol release, were determined during in vitro incubation in all three experiments.3. Plasma concentration of growth hormone was positively and linearly related to dietary reactive CT concentration, whilst 3, 5, 3'-triiodothyronine (T3) concentration tended to be negatively and linearly related to dietary reactive CT concentration. Diet CT concentration had no effect on plasma concentrations of the other hormones measured.4. Feeding of lotus high in CT was associated with a consistent but non-significant increase in the rate of glycerol release from adipose tissue, which was reduced as dietary reactive CT concentration was lowered through PEG application, and a reduction in the lipogenesis: lipolysis value. Selection for leanness decreased acetate incorporation and increased glycerol release from adipose tissue, with the effect not interacting with the diet.

Specificity of insulin or oxytocin stimulation of protein synthesis in adipose tissue

1964 ◽  
Vol 207 (5) ◽  
pp. 1169-1172 ◽  
Author(s):  
M. E. Krahl
Keyword(s):  
Protein Synthesis ◽  
Adipose Tissue ◽  
Glucose Uptake ◽  
Lipid Synthesis ◽  
Specific Effect ◽  
Acetate Incorporation ◽  
Enhance Protein Synthesis ◽  
Rat Adipose Tissue ◽  
Synthetic Oxytocin

Insulin stimulates glucose uptake, fat synthesis, and incorporation of amino acids into protein of rat adipose tissue. Other agents having insulinlike effects on glucose metabolism have now been tested for their ability to promote protein synthesis in this in vitro system. Rat epididymal fat pads were incubated in Krebs bicarbonate medium containing glucose or pyruvate, acetate-1-C14 as precursor for lipids, or (in separate experiments) histidine-2(ring)-C14 as precursor for protein. Glucose uptake was measured by the glucose oxidase method, and radioactivity of lipid and protein fractions was estimated. Synthetic oxytocin (Sandoz), 0.1–10 U/ml, stimulated glucose uptake, acetate incorporation into lipid, and histidine-C14 incorporation into protein when glucose was present; unlike insulin, oxytocin did not enhance protein synthesis when pyruvate replaced glucose in the medium. RNA (1 mg/ml), nicotinic acid (0.001 m), and protamine sulfate (1 mg/ml) each stimulated glucose uptake and acetate incorporation into lipid, but did not enhance histidine-C14 incorporation into protein. It is concluded that in adipose tissue insulin has a specific effect on protein synthesis which cannot be mimicked by other agents which stimulate glucose uptake or lipid synthesis.

ACETATE UTILIZATION BY LIVER AND ADIPOSE TISSUE OF RATS FASTED IN THE COLD

1958 ◽  
Vol 36 (2) ◽  
pp. 237-241 ◽  
Author(s):  
William F. Perry
Keyword(s):  
Carbon Dioxide ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Liver Tissue ◽  
Carbon Dioxide Production ◽  
Acetate Incorporation ◽  
Fasted Rats ◽  
Glucose Supplementation

The in vitro incorporation of 1-C14 and 2-C14 acetate into fatty acids and carbon dioxide by liver and adipose tissue was studied in rats fasted at 5 °C. for 24 hours. Compared with fed rats at room temperature, there was a marked decrease in the incorporation of the acetate carbons into fatty acids and carbon dioxide by liver tissue. A pronounced decrease in acetate incorporation into fatty acid was also noted with adipose tissue from these same animals, but only a slight decrease in incorporation into carbon dioxide. Addition of glucose to the incubation medium caused increases in fatty acid formation by liver and adipose tissue from both normal and fasted animals, but glucose supplementation, while increasing the incorporation of acetate into carbon dioxide by liver tissue from cold fasted rats, did not affect carbon dioxide production by liver tissue from normal animals. Incorporation of acetate into carbon dioxide by adipose tissue was unaffected by glucose supplementation with tissue from both normal and cold fasted rats.

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