ON THE EFFECT OF THE THYROID ON THE METABOLISM OF FREE FATTY ACIDS AND CHOLESTEROL IN FASTING RATS

1966 ◽  
Vol 44 (3) ◽  
pp. 443-449
Author(s):  
V. Felt
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Uric Acid ◽  
Oxygen Consumption ◽  
Free Fatty Acids ◽  
Heart Weight ◽  
Fasting Serum ◽  
Total Body ◽  
Total Body Oxygen

Fasting markedly influences the effect of l-thyroxine on the metabolism of free fatty acids (FFA) and cholesterol in rats. In fed rats thyroxine raises the FFA content of serum and of adipose tissue and increases the liberation of FFA from the latter; in some animals there also occurs an increase in serum cholesterol. These differences are absent in fasting animals. After 48 hours of fasting, serum FFA and FFA liberation from adipose tissue are higher in controls than in thyroxine-treated animals. Total body oxygen consumption remains increased in thyroxine-treated animals even after 48 hours of fasting. Data are given on changes in glycemia, serum uric acid, and heart weight. Phentolamine in vitro was without effect on the liberation of FFA from adipose tissue either in thyroxine-treated animals or in controls.

Effect of nicotine on the mobilization of free fatty acids from adipose tissue in vitro

1969 ◽  
Vol 25 (2) ◽  
pp. 128-128 ◽  
Author(s):  
A. Kershbaum ◽  
H. Osada ◽  
D. J. Pappajohn ◽  
S. Bellet
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Free Fatty Acids ◽  
Adipose Tissue In Vitro

THE STIMULATING EFFECTS OF ADRENALINE AND ANTERIOR PITUITARY HORMONES ON THE RELEASE OF FREE FATTY ACIDS FROM ADIPOSE TISSUE

1962 ◽  
Vol 25 (2) ◽  
pp. 189-198 ◽  
Author(s):  
R. M. BUCKLE
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Pituitary Hormones ◽  
Thyroid Stimulating Hormone ◽  
Adrenocorticotrophic Hormone ◽  
Fat Pads

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.

Effect of β-adrenergic agonists on lipolysis and lipogenesis by porcine adipose tissue in vitro

1990 ◽  
Vol 68 (4) ◽  
pp. 1024-1029 ◽  
Author(s):  
T. A. Peterla ◽  
C. G. Scanes
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Free Fatty Acids ◽  
Direct Effects ◽  
Adrenergic Agonists ◽  
Tissue Explants ◽  
In Vitro Lipolysis ◽  
Adipose Tissue In Vitro ◽  
Release Of Glycerol

Abstract The effects of the β-adrenergic agonists isoproterenol, cimaterol, ractopamine and clenbuterol on lipolysis (release of glycerol and free fatty acids) and lipogenesis (incorporation of 14C into fatty acids from [14C]glucose) was examined in porcine adipose tissue explants in vitro. Lipolysis was stimulated by isoproterenol, cimaterol or ractopamine but not by clenbuterol. Insulin reduced the lipolytic effects of the β-adrenergic agonists (isoproterenol, cimaterol and ractopamine). Lipogenesis was inhibited by all β-adrenergic agonists tested (isoproterenol, cimaterol, ractopamine and clenbuterol). The antilipogenic effect of the β-adrenergic agonists was reduced by the presence of insulin in the incubation. Although effects of the different β-adrenergic agonists varied, all had some direct effects that could be expected to reduce adipose accretion. Effects of β-adrenergic agonists in the pig are due in part to direct effects on adipose tissue.

Net mesenteric and portal absorption and rumen metabolism of volatile fatty acids in forage-fed steers receiving intraruminal propionic acid

1993 ◽  
Vol 1993 ◽  
pp. 54-54 ◽  
Author(s):  
C.J. Seal ◽  
D.S. Parker
Keyword(s):  
Fatty Acids ◽  
Oxygen Consumption ◽  
Energy Consumption ◽  
Gastrointestinal Tract ◽  
Propionic Acid ◽  
Oxidative Metabolism ◽  
Volatile Fatty Acids ◽  
Rumen Metabolism ◽  
Total Body ◽  
Total Body Oxygen

The ability of the gut tissues to absorb nutrients and the extent to which these are then metabolised within the gastrointestinal tract plays a central role in regulating the supply of metabolites to the liver and consequently influences the availability of nutrients for hepatic and peripheral tissue use. Energy consumption by the portal drained viscera is extensive and may account for 25% of total body oxygen consumption (Huntington and Reynolds, 1987). Substrates available for oxidative metabolism include volatile fatty acids (VFA) produced in the rumen and large intestine as addition to arterial supply of these nutrients. The aim of this experiment was to investigate the influence of increased propionate availability on metabolism of VFA in the rumen and the gastrointestinal tract.

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