scholarly journals Clearing-factor lipase in adipose tissue. A possible role of adenosine 3′,5′-(cyclic)-monophosphate in the regulation of its activity

1968 ◽  
Vol 109 (5) ◽  
pp. 841-849 ◽  
Author(s):  
D. R. Wing ◽  
D S Robinson
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Cyclic Amp ◽  
Lipase Activity ◽  
Glucose Concentration ◽  
Free Fatty Acid Concentration ◽  
Epididymal Fat ◽  
Fat Bodies

1. The rise in clearing-factor lipase activity that occurs when epididymal fat bodies from starved rats are incubated in appropriate media in vitro is inhibited in the presence of 6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP (1mm). 2. Inhibition occurs at a concentration of glucose in the incubation medium of 1·3mg./ml. or less, but not at a glucose concentration of 2·4mg./ml., unless caffeine (1mm), an inhibitor of 3′,5′-(cyclic)-nucleotide phosphodiesterase, is also present. Caffeine (5mm) alone inhibits the rise in clearing-factor lipase activity at a glucose concentration of 2·4mg./ml. of medium. 3. The concentration of free fatty acids in the epididymal fat bodies normally falls during incubations in vitro as the rise in clearing-factor lipase activity occurs. In the presence of 1mm-6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP, however, either the tissue free fatty acid concentration is increased or it does not fall to the same extent. The concentration of glucose in the incubation medium is important in determining the direction and extent of the changes in tissue free fatty acid concentration that occur in the presence of 6-N-2′-O-dibutyryl-3′,5′-(cyclic)-AMP. 4. Free fatty acid concentrations in epididymal fat bodies in vivo rise as the clearing-factor lipase activity of the tissue falls during starvation. 5. The possibility that the concentration of 3′,5′-(cyclic)-AMP in adipose tissue may regulate clearing-factor lipase activity, and that the regulation may occur through effects of the nucleotide on tissue free fatty acid concentrations, is discussed.

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.

β-Adrenoceptors mediate inhibition of lipolysis in adipocytes of tilapia (Oreochromis mossambicus)

2002 ◽  
Vol 282 (2) ◽  
pp. E318-E325 ◽  
Author(s):  
Gerjanne J. Vianen ◽  
Peter P. Obels ◽  
Guido E. E. J. M. van den Thillart ◽  
Johan Zaagsma
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Plasma Free Fatty Acid ◽  
Oreochromis Mossambicus ◽  
Plasma Norepinephrine ◽  
In Vivo Experiments ◽  
First Time

The regulation of triglyceride mobilization by catecholamines was investigated in the teleost fish Oreochromis mossambicus (tilapia) in vivo and in vitro. In vitro experiments were carried out with adipocytes that were isolated for the first time from fish adipose tissue. For the in vivo experiments, cannulated tilapia were exposed to stepwise decreasing oxygen levels (20, 10, and 5% air saturation; 3.9, 1.9, and 1.0 kPa Po 2, respectively), each level being maintained for 2 h. Blood samples were taken at timed intervals and analyzed for plasma lactate, glucose, free fatty acids, epinephrine, norepinephrine, and cortisol. Hypoxia exposure did not change plasma epinephrine levels. In contrast, the plasma norepinephrine concentration markedly increased at all hypoxia levels. Over the same period, plasma free fatty acid levels showed a significant continuous decrease, suggesting that norepinephrine is responsible for the reduced plasma free fatty acid concentration, presumably through inhibition of lipolysis in adipose tissue. To elucidate the mechanism, adipocytes were isolated from mesenteric adipose tissue of tilapia and incubated with 1) norepinephrine, 2) norepinephrine + phentolamine (α1,α2-antagonist), 3) isoproterenol (nonselective β-agonist), 4) isoproterenol + timolol (β1,β2-antagonist), 5) norepinephrine + timolol, and 6) BRL-35135A (β3-agonist). The results demonstrate for the first time that norepinephrine and isoproterenol suppress lipolysis in isolated adipocytes of tilapia. The effect of norepinephrine is not mediated through α2-adrenoceptors but, like isoproterenol, via β-adrenoceptors. Furthermore, this study provides strong indications that β3-adrenoceptors are involved.

scholarly journals An ethanolic extract of Artemisia scoparia inhibits lipolysis in vivo and has antilipolytic effects on murine adipocytes in vitro

2018 ◽  
Vol 315 (5) ◽  
pp. E1053-E1061 ◽  
Author(s):  
Anik Boudreau ◽  
Allison J. Richard ◽  
Jasmine A. Burrell ◽  
William T. King ◽  
Ruth Dunn ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Microarray Analysis ◽  
High Fat Diet ◽  
Ethanolic Extract ◽  
High Fat ◽  
Artemisia Scoparia

An ethanolic extract of Artemisia scoparia (SCO) has metabolically favorable effects on adipocyte development and function in vitro and in vivo. In diet-induced obese mice, SCO supplementation significantly reduced fasting glucose and insulin levels. Given the importance of adipocyte lipolysis in metabolic health, we hypothesized that SCO modulates lipolysis in vitro and in vivo. Free fatty acids and glycerol were measured in the sera of mice fed a high-fat diet with or without SCO supplementation. In cultured 3T3-L1 adipocytes, the effects of SCO on lipolysis were assessed by measuring glycerol and free fatty acid release. Microarray analysis, qPCR, and immunoblotting were used to assess gene expression and protein abundance. We found that SCO supplementation of a high-fat diet in mice substantially reduces circulating glycerol and free fatty acid levels, and we observed a cell-autonomous effect of SCO to significantly attenuate tumor necrosis factor-α (TNFα)-induced lipolysis in cultured adipocytes. Although several prolipolytic and antilipolytic genes were identified by microarray analysis of subcutaneous and visceral adipose tissue from SCO-fed mice, regulation of these genes did not consistently correlate with SCO’s ability to reduce lipolytic metabolites in sera or cell culture media. However, in the presence of TNFα in cultured adipocytes, SCO induced antilipolytic changes in phosphorylation of hormone-sensitive lipase and perilipin. Together, these data suggest that the antilipolytic effects of SCO on adipose tissue play a role in the ability of this botanical extract to improve whole body metabolic parameters and support its use as a dietary supplement to promote metabolic resiliency.

Effect of prolactin on lipoprotein lipase in crop sac and adipose tissue of pigeons

1975 ◽  
Vol 228 (5) ◽  
pp. 1542-1544 ◽  
Author(s):  
MM Garrison ◽  
RO Scow
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Lipoprotein Lipase ◽  
Adult Female ◽  
Lipase Activity ◽  
Milk Lipid ◽  
Lipoprotein Lipase Activity ◽  
Omental Adipose Tissue ◽  
Chylomicron Triglyceride

The effect of prolactin on lipoprotein lipase activity of crop sac, omental adipose tissue, and esophagus was studied in adult female pigeons. Prolactin injected for 4 days, 1 mg/day, increased lipoprotein lipase activity from 17 to 177 U/g in crop sac and from 68 to 118 U/g in adipose tissue, but had no effect on the activity in esophagus, 4 U/g. (10 = 1 mumol of chylomicron triglyceride hydrolyzed to free fatty acid and glycerol per hour.? Prolactin increased the weight of crop sac from 1.4 to 7.2 G. The effect of prolactin on lipoprotein lipase activity and weight of crop sac occurred mostly during the 3rd and 4th days of treatment, whereas the effect on the activity of adipose tissue occurred later, during the 4th day of treatment. Crop "milk" collected from pigeons injected with 2 mg of prolactin daily for 4 days contained a small amount of lipoprotein lipase activity, 12 U/g, is smaller than 10% of that found in crop sac. The finding of markedly increased lipoprotein lipase activity in crop sac of prolactin-treated pigeons suggests that blood triglyceride may be used by crop sac for the formation of crop milk lipid.

Fetal lipoproteins and placental release of esterified lipids

1996 ◽  
Vol 8 (3) ◽  
pp. 457 ◽  
Author(s):  
JP Stammers ◽  
TJ Stephenson ◽  
JA Colley ◽  
D Hull
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Late Gestation ◽  
Free Fatty Acid Concentration ◽  
Fatty Acid Profiles ◽  
Rabbit Plasma ◽  
Albumin Solution ◽  
Series Of Experiments

An in vitro incubation technique was used to examine the release of lipids from the rabbit placenta. Free fatty acid, but not phospholipid or triacylglycerol, was released into the incubation media. In a second series of experiments, the addition of lipids to the umbilical circulation was studied in situ in the placenta of anaesthetized rabbits at late gestation. Each placenta was perfused from the fetal side in turn with two different perfusate solutions, either 4% bovine albumin solution or rabbit plasma. The rabbit plasma contained the appropriate carriers (lipoproteins) for esterified lipids, whereas the 4% albumin solution did not. The effluent perfusates were remarkably similar in free fatty acid concentration and composition, which closely matched the maternal free fatty acid profiles. The concentrations and fatty acid composition of the perfusate triacylglycerol and phospholipid fractions were unchanged by passage through the placenta, whether perfused with 4% albumin or with rabbit plasma. With this system, no evidence could be found for the addition of esterified lipids to the umbilical circulation in the rabbit despite the provision of appropriate carriers on the fetal side of the placenta.

scholarly journals Production of Endogenous Acetate by the Liver in Lactating Ewes

1976 ◽  
Vol 29 (2) ◽  
pp. 33 ◽  
Author(s):  
N D Costa ◽  
GH Mclntosh ◽  
AM Snoswell
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Venous Blood ◽  
Free Fatty Acid Concentration ◽  
Acetate Production ◽  
Hepatic Venous Blood ◽  
The Mean

The production of endogenous acetate by the liver has been investigated in lactating ewes using animals with indwelling arterial, and portal and hepatic venous cannulae. The capacity of the liver to produce acetate from acetyl-CoA in vitro has also been examined using homogenates prepared from liver biopsy samples. Mean arterial, portal and hepatic venous blood acetate concentrations in four ewes at 4 weeks lactation were 0'40, 1�00 and 1�46 mM respectively. The mean exogenous and endogenous acetate production rates were 56 and 54 mmol/h respectively, giving a total of 110 mrnol/h. The mean portal-hepatic venous difference in free fatty acid concentration was 81 11M. Converting this uptake of free fatty acids by the liver (based on palmitate as a standard) to 2-carbon equivalents, the acetate produced accounted for 70 % of the fatty acids taken up. The correlation coefficient (r2) between uptake of free fatty acids and production of acetate by the liver was o� 83 (P < O� 01),

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