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.

scholarly journals Studies on lipid digestion in the preruminant calf

1978 ◽  
Vol 40 (1) ◽  
pp. 125-131 ◽  
Author(s):  
J. D. Edwards-Webb ◽  
S. Y. Thompson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Butyric Acid ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Esterified Fatty Acids ◽  
Chain Fatty Acids

1. The lipolysis of cow's milk fat by salivary lipase (EC 3.1.1.3) in the preruminant calf has been studied in vitro by a simulated abomasal digestion, and also in vivo by examining the abomasal effluent collected over 12 h after giving whole milk to a calf.2. In the in vitro experiment the liquid drained from the clot contained a higher proportion of short-chain fatty acids than the abomasal effluent in the in vivo experiment. This was considered to indicate the absorption of short-chain free fatty acids from within the abomasum.3. Preferential release of short-chain fatty acids both in vitro and in vivo was observed.4. The outflow of butyric acid from the abomasum of the calf was initially rapid, but had levelled off at approximately 6 h, whereas the outflow of a typical long-chain fatty acid (palmitic) was fairly constant over the 12 h.Butyric acid predominated in the free fatty acids of abomasal effluent 0.5 h after feeding (668 mmol/mol total free fatty acids) but had become a minor component by 12 h (15 mmol/mol total free fatty acids).5. The mean amounts of free and esterified fatty acids (mmol/mol fatty acid ingested) present in the abomasal effluent from the 12 h collection period were: triglyceride 465, diglyceride 215, monoglyceride 68, free fatty acid 252. These values showed that only one-third of esterified fatty acids ingested are lipolysed to absorbable products by salivary lipase.

Utilization of free fatty acids by diaphragm in vitro

1962 ◽  
Vol 203 (2) ◽  
pp. 311-315 ◽  
Author(s):  
P. T. Bodel ◽  
D. Rubinstein ◽  
E. E. McGarry ◽  
J. C. Beck
Keyword(s):  
Fatty Acids ◽  
Growth Hormone ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Gastrocnemius Muscle ◽  
Rat Diaphragm ◽  
Diaphragm In Vitro

Human and rat diaphragm and rat gastrocnemius muscle oxidize and esterify palmitate-1-C14. Incorporation of C14 was found to be in proportion to the palmitate present in the medium over a range of concentrations from 0.8 to 2.9 µEq/ml. Fasting increased C14O2 production but had no effect on esterification. Iodoacetate or an atmosphere of nitrogen inhibited esterification of palmitate but increased the amount of free fatty acid in the tissue. Insulin increased esterification, and this was enhanced by the addition of glucose. Glucose and insulin exerted a sparing action on the oxidation of glycerides by a tissue previously charged with palmitate-1-C14. Growth hormone administered in vivo over a period of 1 week or in vitro during incubation had no effect on esterification or metabolism of palmitate-1-C14.

Rapid in vivo hydrolysis of fatty acid ethyl esters, toxic nonoxidative ethanol metabolites

1997 ◽  
Vol 273 (1) ◽  
pp. G184-G190 ◽  
Author(s):  
M. Saghir ◽  
J. Werner ◽  
M. Laposata
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Ethyl Esters ◽  
Ethyl Esters ◽  
Ethanol Ingestion ◽  
Gi Tract ◽  
Apparent Lack ◽  
Hydrolysis Of

Fatty acid ethyl esters (FAEE), esterification products of fatty acids and ethanol, are in use as fatty acid supplements, but they also have been implicated as toxic mediators of ethanol ingestion. We hypothesized that hydrolysis of orally ingested FAEE occurs in the gastrointestinal (GI) tract and in the blood to explain their apparent lack of toxicity. To study the in vivo inactivation of FAEE by hydrolysis to free fatty acids and ethanol, we assessed the hydrolysis of FAEE administered as an oil directly into the rat stomach and when injected within the core of low-density lipoprotein particles into the circulation of rats. Our studies demonstrate that FAEE are rapidly degraded to free fatty acids and ethanol in the GI tract at the level of the duodenum with limited hydrolysis in the stomach. In addition, FAEE are rapidly degraded in the circulation, with a half-life of only 58 s. Thus the degradation of FAEE in the GI tract and in the blood provides an explanation for the apparent lack of toxicity of orally ingested FAEE.

Lipid and glycogen metabolism in the hypoxic heart: effects of epinephrine

1975 ◽  
Vol 229 (4) ◽  
pp. 885-889 ◽  
Author(s):  
Crass MF ◽  
GM Pieper
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Oxidation ◽  
Glycogen Metabolism ◽  
Acid Oxidation ◽  
Triglyceride Fatty Acid ◽  
Rat Hearts ◽  
Perfused Rat Hearts

The metabolism of cardiac lipids and glycogen in hypoxic and well-oxygenated perfused rat hearts was studied in the presence or absence of epinephrine. Heart lipids were pre-labeled in vivo with [1-14C]palmitate. Triglyceride disappearance (measured chemically and radiochemically) was observed in well-oxygenated hearts and was stimulated by epinephrine (4.1 X 10(-7)M). Utilization of tissue triglycerides was inhibited in hypoxic hearts in the presence or absence of added epinephrine. Hypoxia resulted in a small increase in tissue 14C-free fatty acids and inhibition of 14C-labeled triglyceride fatty acid oxidation. Epinephrine had no stimulatory effect on fatty acid oxidation in hypoxic hearts. Utilization of 14C-labeled phospholipids (and total phospholipids) was similar in well-oxygenated and hypoxic hearts with or without added epinephrine. These results suggested that the antilipolytic effects of hypoxia were predominant over the lipolytic effects of epinephrine. Glycogenolysis was stimulated threefold by epinephrine in well-oxygenated hearts. Hypoxia alone was a potent stimulus to glycogenolysis. Addition of epinephrine to perfusates of hypoxic hearts resulted in a slight enhancement of glycogenolysis.

Effects of epinephrine on regional free fatty acid and energy metabolism in men and women

1996 ◽  
Vol 270 (2) ◽  
pp. E259-E264 ◽  
Author(s):  
M. D. Jensen ◽  
P. E. Cryer ◽  
C. M. Johnson ◽  
M. J. Murray
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Fat Distribution ◽  
Normal Weight ◽  
Upper Body ◽  
Lower Body ◽  
Men And Women

Upper-body and lower-body adipocytes respond differently to physiological catecholamines in vitro. It is not known whether this is true in vivo or whether gender differences exist in the regional adipose tissue responses to epinephrine. These studies were therefore conducted to examine free fatty acid (FFA) release ([3H]palmitate) from lower-body (leg), splanchnic, and upper-body adipose tissue in normal-weight adult men (n = 8) and women (n = 7). In response to intravenous epinephrine (10 ng.kg-1.min-1), palmitate release increased (P < 0.01) in both men (168 +/- 10 to 221 +/- 15 mumol/min) and women (177 +/- 12 to 234 +/- 18 mumol/min). Basal leg palmitate release was similar in women and men (16.8 +/- 2.9 and 12.4 +/- 1.3 mumol/min, P = not significant) but doubled (P < 0.01) in response to epinephrine in men and was virtually unchanged in women. Splanchnic palmitate release increased (P < 0.05) in men (n = 6) but not in women (n = 6), whereas nonsplanchnic upper-body palmitate release increased more in women than in men. Upper-body (splanchnic and nonsplanchnic) palmitate release increased (P < 0.05) in both men and women in response to epinephrine. In summary, lower-body adipose tissue FFA release increased in response to epinephrine in men but not women, whereas upper-body palmitate release increased in both groups. These findings are consistent with some in vitro findings and suggest that catecholamine action may play a role in determining gender-based differences in body fat distribution.

Adipose tissue in experimental nephrotic syndrome

1963 ◽  
Vol 205 (4) ◽  
pp. 702-706 ◽  
Author(s):  
Alisa Gutman ◽  
Eleazar Shafrir
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Nephrotic Syndrome ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Lipoprotein Lipase ◽  
Epididymal Adipose Tissue ◽  
Adequate Nutrition ◽  
Defective Metabolism ◽  
Inadequate Food Intake

Epididymal adipose tissue of aminonucleoside-treated rats, investigated 3 to 6 days after induction of the nephrotic syndrome, had low glycogen levels and showed impaired esterification of free fatty acids and assimilation of lipoprotein triglyceride and markedly reduced liberation of lipoprotein lipase. These results were found to be influenced by the inadequate food intake of the acutely nephrotic animals and comparable to the values of control rats fasted for 2 days. On return to adequate nutrition, which occurred 12–20 days after aminonucleoside treatment, adipose tissue glycogen and free fatty acid assimilation returned toward normal levels but lipoprotein-lipase liberation remained below normal. In rats rendered nephrotic by antikidney serum, the assimilation of free fatty acids and lipoprotein-triglyceride by adipose tissue was impaired in spite of only minor reduction in food consumption. The results indicate that the defective metabolism of adipose tissue in nephrotic animals may be contributory to the nephrotic hypertriglyceridemia.

Uptake and compartmental distribution of fatty acid by rat small intestine in vivo

1975 ◽  
Vol 228 (5) ◽  
pp. 1409-1414
Author(s):  
S Mishkin ◽  
M Yalovsky ◽  
JI Kessler
Keyword(s):  
Fatty Acids ◽  
Small Intestine ◽  
Fatty Acid ◽  
Entire Length ◽  
Rat Small Intestine ◽  
Pass Through

The uptake and esterification of micellar [3-H]oleate and [14-C] palmitate were uniform along the entire length of the small intestine in vivo. Fatty acids (FA) radioactivity taken up by the small intestine could be described in terms of four functionally distinct compartments analogous to those described in vitro. The KRP-extractable compartment (KEC) and albumin-extractable compartment (AEC) contained reversibly adherent unesterified FA radioactivity, while the tissue free and esterified FA compartments contained irreversibly bound radioactivity. Wheras 27% and 63% of FA uptake were reversibly bound in the KEC and AEC by the most proximal and most distal regions of the small intestine in vitro (15), less than 10% was contained in these compartments in vivo, independent of location. Linear inverse relationships were found betweeen tissue FA esterification and proportion of FA radioactivity present in the KEC,AEC, and the tissue free FA compartment in vivo. These observations allow for the possibility that FA molecules pass through these compartments prior to esterification.

Lipid Labelling in Intact Chloroplasts from Exogenous Nucleotide Precursors

1981 ◽  
Vol 36 (1-2) ◽  
pp. 62-70 ◽  
Author(s):  
Margrit Bertrams ◽  
Käthe Wrage ◽  
Ernst Heinz
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
De Novo ◽  
Membrane System ◽  
Chloroplast Envelope ◽  
Label Free ◽  
Intact Chloroplasts ◽  
Time Required

Abstract De novo-synthesis of glycerolipids in chloroplasts is initiated by a stroma enzyme which catalyzes the formation of lyso-phosphatidic acid from glycerophosphate and acyl-CoA. When these substrates are added to isolated, intact chloroplasts, only glycerophosphate can readily pass through the chloroplast envelope which represents a permeation barrier for acyl-CoA, although higher thioester concentrations destroy this membrane system. At low concentrations of acyl-CoA, which do not impair the envelope, intact chloroplasts metabolize exogenous acyl-CoA in two ways to give free fatty acids and labelled phosphatidyl choline. This indicates that the envelope thioesterase can use exogenous substrates. Isolated, intact chloroplasts fixing radioactive CO2 label free fatty acids and acylglycerols but not galactolipids, since they cannot convert 3-phosphoglycerate into UDP-galactose which in vivo is supplied by the cytoplasm. This cooperation was simulated in vitro by adding all enzymes and cofactors necessary for conversion of 3-phosphoglycerate into UDP-galactose to intact chloro­plasts which then formed labelled monogalactosyl diacylglycerol from labelled CO2. The time required to transfer envelope-made galactolipids from the envelope into thylakoids was studied by incubating intact chloroplasts with radioactive UDP-galactose, subsequent osmotic disruption of organelles with concomitant enzymatic degradation of UDP-galactose followed by separation of envelopes and thylakoids. Only after short times (< 1min) appreciable proportions 920-30%) of radioactive galactolipid export from envelopes into thylakoids.

Effect of exercise on hormone-sensitive lipase activity in rat adipocytes

1976 ◽  
Vol 230 (2) ◽  
pp. 385-388 ◽  
Author(s):  
JA McGarr ◽  
LB Oscai ◽  
J Borensztajn
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Adipose Tissue ◽  
Free Fatty Acids ◽  
Lipase Activity ◽  
Exercise Program ◽  
Treadmill Running ◽  
Hormone Sensitive Lipase ◽  
Hormone Sensitive ◽  
Fat Pads

Hormone-sensitive lipase activity was measured in adipocytes of rats subjected to a 12-wk program of treadmill running. Enzyme activity in the runners sacrificed immediately after exercise increased 2.5-fold (P less than 0.001) in tissue exposed to epinephrine and threefold (P less than 0.001) in tissue not exposed to epinephrine, when the results were expressed per gram of adipose tissue. Increases of almost the same magnitude were observed in runners sacrificed 24 h after their last bout of work. These significant increases in enzyme activity, however, were the result of a significant reduction in the size of cells in the epididymal fat pads of the exercisers compared with those of the freely eating sedentary animals (68.7 +/- 2.7 mum vs. 82.0 +/- 2.7 mum; P less than 0.01). When the results were expressed on a per-cell basis, therefore, hormone-sensitive lipase activity, assayed in the presence or absence of epinephrine, was unaffected by the exercise program. These results provide evidence that the lipolytic capacity of adipocytes of normal, untrained rats is sufficiently large to meet the increased demand for free fatty acids imposed by the exercise program without the need for an adaptive increase in enzyme activity.

Adenosine regulates blood flow and glucose uptake in adipose tissue of dogs

1986 ◽  
Vol 250 (6) ◽  
pp. H1127-H1135
Author(s):  
S. E. Martin ◽  
E. L. Bockman
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Glucose Uptake ◽  
Indirect Effect ◽  
Glycerol Release ◽  
Anesthetized Dogs ◽  
Tissue Contents ◽  
Fat Pads

Intravenous norepinephrine increases glycerol release and blood flow in adipose tissue. The vasodilation may be an indirect effect of norepinephrine through the production of adenosine. Adenosine increases glucose uptake and inhibits lipolysis in vitro. To test whether adenosine regulates blood flow and/or metabolism in vivo, adenosine deaminase (ADA) was infused intra-arterially into the inguinal fat pads of anesthetized dogs. In unstimulated tissues, ADA (n = 7) significantly increased vascular resistance and significantly decreased glucose uptake compared with the effects of a control (boiled deaminase, n = 6) infusion. ADA completely blocked the norepinephrine-induced vasodilation (n = 6). No potentiation of basal or catecholamine-stimulated lipolysis was observed with ADA. The presence of ADA in the interstitial space was verified by analysis of lymph effluents. Interstitial levels of ADA were inversely correlated with the tissue contents of adenosine. These data support the hypothesis that adenosine is a regulator of blood flow in basal and stimulated adipose tissue. Adenosine also appears to regulate glucose uptake, but not lipolysis, in vivo.

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