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

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.

1958 ◽  
Vol 36 (1) ◽  
pp. 237-241
Author(s):  
William F. Perry

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.


1961 ◽  
Vol 39 (6) ◽  
pp. 1061-1065 ◽  
Author(s):  
W. F. Perry ◽  
Helen F. Bowen

The in vitro utilization of non-esterified fatty acids by various tissues and the in vitro production of non-esterified fatty acids by adipose tissue have been compared in normal and adrenalectomized rats. It was found that the production of NEFA by adipose tissue was similar in both groups of animals but that the in vitro utilization of NEFA and production of carbon dioxide by heart, diaphragm, kidney, and liver tissue was greater in the adrenalectomized animal. These findings together with the depletion of fat content of the depots are interpreted as indicating that in the adrenalectomized state there is increased peripheral utilization of fatty acids.


1985 ◽  
Vol 68 (1) ◽  
pp. 83-88 ◽  
Author(s):  
C. Stirling ◽  
M. McAleer ◽  
J. P. D. Reckless ◽  
R. R. Campbell ◽  
D. Mundy ◽  
...  

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.


2018 ◽  
Author(s):  
Stephanie Adolph ◽  
Carola Schedlbauer ◽  
Dominique Blaue ◽  
Axel Schöniger ◽  
Claudia Gittel ◽  
...  

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.


1962 ◽  
Vol 25 (2) ◽  
pp. 189-198 ◽  
Author(s):  
R. M. BUCKLE

SUMMARY The quantity of free fatty acids (FFA) released from rat epididymal fat pads in vitro and their concentration within the tissue were determined. The addition of adrenaline, adrenocorticotrophic hormone (ACTH), thyroid stimulating hormone (TSH) and growth hormone (GH) each increased the release of FFA, and their respective minimum effective concentrations were 0·125, 0·004, 0·5 and 1·25 μg./ml. of medium. In every case, the increased release of FFA was associated with a rise in the quantity present within the pads, and the amount released closely paralleled their concentration within the tissue. It is suggested that the stimulatory effect of all four hormones on the release of FFA from adipose tissue is largely a manifestation of their activity of increasing the concentration of FFA within the cells, and this they do by facilitating the net conversion of storage triglyceride to fatty acid. The significance of the relative activities of the hormones in vitro is discussed and compared with their fatty acid mobilizing effects in vivo.


1957 ◽  
Vol 35 (1) ◽  
pp. 759-766 ◽  
Author(s):  
W. F. Perry ◽  
Helen F. Bowen

The effect of growth hormone on the in vitro incorporation of C14 acetate into fatty acids, carbon dioxide, and cholesterol by liver and adipose tissue from young, adult, and old rats was studied.In all three age groups of animals, growth hormone was found to depress the incorporation of acetate into fatty acids by liver slices but the CO2 production was unaffected. In both young and old animals growth hormone did not significantly alter the incorporation of acetate into fatty acids and CO2 by preparations of adipose tissue, but did result in a decline in the fat content of the adipose tissue. It was noted that the CO2 production from acetate was much less with adipose tissue from old rats than with similar preparations from young rats.Incorporation of acetate into cholesterol was unaffected by growth hormone in young and old animals but was significantly increased in liver slices from adult animals.


1957 ◽  
Vol 189 (3) ◽  
pp. 433-436 ◽  
Author(s):  
W. F. Perry ◽  
Helen F. Bowen

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.


1969 ◽  
Vol 44 (1) ◽  
pp. 115-119 ◽  
Author(s):  
J. ŠKARDA ◽  
S. BARTOŠ

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.


1983 ◽  
Vol 244 (5) ◽  
pp. E480-E486 ◽  
Author(s):  
B. Kalderon ◽  
J. H. Adler ◽  
E. Levy ◽  
A. Gutman

Synthesis of fatty acids was measured in the liver and in epididymal adipose tissue of sand rats and albino rats. In chow-fed sand rats the rate of hepatic lipogenesis, as measured by the incorporation of 3H2O into fatty acids, was four- to sevenfold higher than in albino rats and in sand rats on a low-calorie saltbush diet. The contribution of [14C]glucose to lipogenesis in sand rat liver was lower than in albino rats. In fed sand rats lipogenesis incorporating 3H2O was stimulated by casein but not by glucose. In adipose tissue, lipogenesis measured 1 h after administration of 3H2O was much lower in sand rats than in albino rats. In vitro incorporation of [14C]glucose or acetate into adipose tissue fatty acids was negligible. In adipose tissue, uptake of very-low-density lipoproteins (VLDL) and lipoprotein lipase activity were sevenfold higher than in albino rats. Activities of NADP-malate dehydrogenase, acetyl CoA carboxylase, and fatty acid synthetase were considerably higher in the liver of chow-fed sand rats than in albino rats. It was concluded that obesity in sand rats originates from hepatic lipogenesis without a significant contribution of local fatty acid synthesis in adipose tissue.


1957 ◽  
Vol 35 (9) ◽  
pp. 759-766 ◽  
Author(s):  
W. F. Perry ◽  
Helen F. Bowen

The effect of growth hormone on the in vitro incorporation of C14 acetate into fatty acids, carbon dioxide, and cholesterol by liver and adipose tissue from young, adult, and old rats was studied.In all three age groups of animals, growth hormone was found to depress the incorporation of acetate into fatty acids by liver slices but the CO2 production was unaffected. In both young and old animals growth hormone did not significantly alter the incorporation of acetate into fatty acids and CO2 by preparations of adipose tissue, but did result in a decline in the fat content of the adipose tissue. It was noted that the CO2 production from acetate was much less with adipose tissue from old rats than with similar preparations from young rats.Incorporation of acetate into cholesterol was unaffected by growth hormone in young and old animals but was significantly increased in liver slices from adult animals.


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