scholarly journals Fatty acids synthesis in rat adipose tissue. Tracer concentration effects in vitro

1968 ◽  
Vol 106 (1) ◽  
pp. 179-183 ◽  
Author(s):  
W. G. Duncombe
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Acid Synthesis ◽  
Long Chain Fatty Acids ◽  
Concentration Effects ◽  
Tracer Concentration ◽  
Adipose Tissue In Vitro ◽  
Rat Adipose Tissue ◽  
Long Chain

1. The use of labelled acetate for studying the synthesis of long-chain fatty acids in rat adipose tissue in vitro has been examined, with special reference to the effect of acetate concentration. 2. The incorporation of acetate into fatty acids is proportional to the concentration of acetate in the medium when the latter does not exceed about 10μm. Above this concentration, the relative incorporation becomes progressively less, and reasons for this are discussed. 3. In particular it is shown that this is not necessarily due to disturbance of the endogenous rate of fatty acid synthesis by a relatively large amount of acetyl-CoA derived from added acetate. 4. However, to ensure that the added acetate does not cause such a disturbance its concentration must be kept sufficiently low. For labelled acetate used under present conditions, this concentration should not be more than about 10μm.

ESTERIFICATION OF INTRA- AND EXTRA-CELLULAR FREE FATTY ACIDS BY RAT ADIPOSE TISSUE

1965 ◽  
Vol 43 (6) ◽  
pp. 635-645 ◽  
Author(s):  
David Rubinstein ◽  
Anna M. Daniel ◽  
Lydia Lechter ◽  
John C. Beck
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Incubation Medium ◽  
Neutral Lipids ◽  
Long Chain Fatty Acids ◽  
Adipose Tissue In Vitro ◽  
Rat Adipose Tissue ◽  
Glycerol Esterification ◽  
Long Chain

The esterification of intracellular and extracellular FFA by rat adipose tissue in vitro was investigated. The rate of incorporation of FFA into neutral lipids was proportional to the FFA concentration in the incubation medium. Both in the presence and absence of a lipolytic agent (epinephrine), heptadecanoate-1-C14, which is not specifically diluted by tissue fatty acids, was esterified in the same manner as palmitate-9,10-H3. Stearate, palmitate, and oleate were esterified at similar rates by adipose tissue taken from fed animals and incubated with glucose. The rate of esterification of one fatty acid was not significantly affected by the presence of another. Similar results were obtained when tissues were taken from fasted animals and incubated in the absence of glucose, except that the overall rate of esterification was diminished and FFA accumulated in the tissue. It is concluded that long-chain fatty acids do not compete for esterification or entry into the adipose tissue cell.In some experiments tissue FFA esterification was studied by measuring the incorporation of glucose-U-C14 carbons into glyceride–glycerol. Esterification, assayed in this manner, increased when albumin was present in the incubation medium and allowed FFA to diffuse from the tissue. However, pre-incubation of adipose tissue in medium containing labelled FFA indicates that much of the intracellular FFA may be esterified without its mixing with the extracellular FFA pool.

scholarly journals Interactions of insulin, corticosterone and prolactin in promoting milk-fat synthesis by mammary explants from pregnant rabbits

1972 ◽  
Vol 129 (4) ◽  
pp. 929-935 ◽  
Author(s):  
Isabel A. Forsyth ◽  
Christopher R. Strong ◽  
Raymond Dils
Keyword(s):  
Fatty Acids ◽  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Long Chain Fatty Acids ◽  
Medium Chain ◽  
Long Chain ◽  
Chain Fatty Acids

1. The rate of fatty acid synthesis by mammary explants from rabbits pregnant for 16 days or from rabbits pseudopregnant for 11 days was stimulated up to 15-fold by culturing for 2–4 days with prolactin. This treatment initiated the predominant synthesis of C8:0 and C10:0 fatty acids, which are characteristic of rabbit milk. 2. Inclusion of insulin in the culture medium increased the rate of synthesis of these medium-chain fatty acids. By contrast the inclusion of corticosterone led to the predominant synthesis of long-chain fatty acids. When explants were cultured for 2–4 days with insulin, corticosterone and prolactin, the rate of fatty acid synthesis increased up to 42-fold, but both medium- and long-chain fatty acids were synthesized. 3. These results show that the stimulus to mammary-gland lipogenesis and the initiation of synthesis of medium-chain fatty acids observed between days 16 and 23 of pregnancy in the rabbit can be simulated in vitro by prolactin alone. 4. When mammary explants from rabbits pregnant for 23 days were cultured for 2 days with insulin, corticosterone and prolactin, the rate of fatty acid synthesis increased fivefold, but there was a preferential synthesis of long-chain fatty acids. Culture with prolactin alone had little effect on the rate or pattern of fatty acids synthesized. 5. The results are compared with findings in vivo on the control of lipogenesis in the rabbit mammary gland, and are contrasted with the known effects of hormones in vitro on the mammary gland of the mid-pregnant mouse.

scholarly journals Effects of Prolactin in Vitro on Fatty Acid Synthesis in Rat Adipose Tissue

1959 ◽  
Vol 234 (12) ◽  
pp. 3111-3114 ◽  
Author(s):  
Albert I. Winegrad ◽  
Walter N. Shaw ◽  
Francis D.W. Lukens ◽  
William C. Stadie
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Rat Adipose Tissue

Effects of cold acclimation on lipid metabolism in adipose tissue

1961 ◽  
Vol 200 (4) ◽  
pp. 847-850 ◽  
Author(s):  
Judith K. Patkin ◽  
E. J. Masoro
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Cold Acclimation ◽  
Long Chain Fatty Acids ◽  
Synthetic Capacity ◽  
And Control ◽  
Long Chain ◽  
Chain Fatty Acids

Cold acclimation is known to alter hepatic lipid metabolism. Liver slices from cold-acclimated rats have a greatly depressed capacity to synthesize long-chain fatty acids from acctate-1-C14. Since adipose tissue is the major site of lipogenic activity in the intact animal, its fatty acid synthetic capacity was studied. In contrast to the liver, it was found that adipose tissue from the cold-acclimated rat synthesized three to six times as much long-chain fatty acids per milligram of tissue protein as the adipose tissue from the control rat living at 25°C. Evidence is presented indicating that adipose tissue from cold-acclimated and control rats esterify long-chain fatty acids at the same rate. The ability of adipose tissue to oxidize palmitic acid to CO2 was found to be unaltered by cold acclimation. The fate of the large amount of fatty acid synthesized in the adipose tissue of cold-acclimated rats is discussed.

Effects of hormones on cyclic AMP release from rat adipose tissue in vitro

FEBS Letters ◽  
1974 ◽  
Vol 49 (1) ◽  
pp. 65-69 ◽  
Author(s):  
P. Zumstein ◽  
J. Zapf ◽  
E.R. Froesch
Keyword(s):  
Adipose Tissue ◽  
Cyclic Amp ◽  
Adipose Tissue In Vitro ◽  
Rat Adipose Tissue

scholarly journals Acute exposure to long-chain fatty acids impairs α2-adrenergic receptor-mediated antilipolysis in human adipose tissue

2007 ◽  
Vol 48 (10) ◽  
pp. 2236-2246 ◽  
Author(s):  
Jan Polak ◽  
Cédric Moro ◽  
David Bessière ◽  
Jindra Hejnova ◽  
Marie A. Marquès ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Adrenergic Receptor ◽  
Human Adipose Tissue ◽  
Acute Exposure ◽  
Long Chain Fatty Acids ◽  
Long Chain ◽  
Chain Fatty Acids
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