scholarly journals The effects of diet on the esterification of glycerol phosphate, dihydroxyacetone phosphate and 2-hexadecylglycerol by homogenates of rat adipose tissue

1976 ◽  
Vol 160 (3) ◽  
pp. 701-706 ◽  
Author(s):  
P F Dodds ◽  
D N Brindley ◽  
M I Gurr
Keyword(s):  
Adipose Tissue ◽  
Beef Tallow ◽  
Corn Oil ◽  
Specific Activity ◽  
Body Weight Gain ◽  
Male Rats ◽  
Dihydroxyacetone Phosphate ◽  
Glycerol Phosphate ◽  
Triacylglycerol Content ◽  
Rat Adipose Tissue

1. Male rats were fed for 5 weeks after weaning on a diet containing (by weight) 59% of starch or on diets that contained 39% of starch and 20% of either sucrose, beef tallow or corn oil. 2. The rats fed on the beef tallow consumed more energy than did the rats fed on the starch and sucrose diets. The rats fed on the corn oil drank less water than did the other groups of rats. 3. There were no significant differences between the four groups in terms of body-weight gain, epididymal-fat-pad weight and in the size, number and triacylglycerol content of the adipocytes in the fat-pads. 4. There was a significant correlation (P < 0.001) between the activities of glycerol phosphate acyltransferase and monoacylglycerol acyltransferase in individual rats. Both of these activities were highest in the group fed on the high-starch diet and both correlated with the consumption of glucose by individual rats in the four groups. 5. The percentage of glycerol phosphate converted into diacylglycerol and triacylglycerol was positively correlated with the mean diameters, surface area and triacylglycerol content of the adipocytes for individual rats and was greates in the sucrose-fed rats. 6. The specific activity of dihydroxyacetone phosphate acyltransferase was highest in the rats fed on beef tallow. This activity was positively correlated with the energy intake for all dietary groups over the 5-week feeding period. 7. The results are discussed in terms of the functions of the three routes of glycerolipid synthesis in adipose tissue.

scholarly journals Effects of chronic modification of dietary fat and carbohydrate in rats. The activities of some enzymes of hepatic glycerolipid synthesis and the effects of corticotropin injection

1981 ◽  
Vol 200 (2) ◽  
pp. 265-273 ◽  
Author(s):  
N Lawson ◽  
R J Jennings ◽  
A D Pollard ◽  
R G Sturton ◽  
S J Ralph ◽  
...  
Keyword(s):  
Beef Tallow ◽  
Corn Oil ◽  
Urate Oxidase ◽  
Dihydroxyacetone Phosphate ◽  
High Fat ◽  
Glycerol Phosphate ◽  
Acyltransferase Activity ◽  
High Fat Diets ◽  
Fat Diets ◽  
Starch Diet

1. Rats were fed on diets enriched with starch, sucrose, corn oil or beef tallow for 3 weeks and the activities of various enzymes in the liver were measured. 2. The mitochondrial glycerol phosphate acyltransferase activity was lower in rats fed on the starch diet than on the two high-fat diets. 3. The non-microsomal (presumably peroxisomal) dihydroxyacetone phosphate acyltransferase activity was higher in rats fed on the starch diet and corn-oil diets than in those fed on the sucrose and beef-tallow diets. Urate oxidase activity was higher in rats fed on the starch diet than in the three other groups. There were no significant differences in the activity of acyl-CoA oxidase among the groups. 4. The activity of soluble phosphatidate phosphohydrolase was not significantly different among the dietary groups. There were increases of 3.3--4.3-fold in this activity in the dietary groups 6h after injection of corticotropin. The equivalent increases for the mitochondrial glycerol phosphate acyltransferase were 1.4--1.6 fold. 5. The corticosterone responses to the corticotropin injection were not significantly different between dietary groups. However, the corticosterone response of the rats fed on the two high-fat diets was prolonged when the rats were given an acute load of fructose [Brindley, Cooling, Glenny, Burditt & McKechnie (1981) Biochem. J. 200. 275--283]. 6. Rats fed on the high-fat diets had higher concentrations of circulating cholesterol than those fed on the starch and sucrose diets. Serum triacylglycerol concentrations were lower in the rats fed on the starch diet than in the three other groups. 7. The results are discussed in terms of the relationship between diet, hormonal balance and hepatic glycerolipid metabolism.

scholarly journals The effect of dietary carbohydrate and fat on the activities of some enzymes responsible for glycerolipid synthesis in rat liver

1978 ◽  
Vol 174 (2) ◽  
pp. 535-541 ◽  
Author(s):  
H P Glenny ◽  
M Bowley ◽  
S L Burditt ◽  
J Cooling ◽  
P H Pritchard ◽  
...  
Keyword(s):  
Corn Oil ◽  
Specific Activity ◽  
Male Rats ◽  
Dihydroxyacetone Phosphate ◽  
Triacylglycerol Synthesis ◽  
Choline Phosphotransferase ◽  
Phosphatidate Phosphohydrolase ◽  
Glycerolipid Synthesis ◽  
Starch Diet

1. Male rats were fed for 14 days on diets containing (by wt.) 53% of starch, or on diets in which 20% of the starch was replaced by sucrose, corn oil or lard. 2. The hepatic activities of the microsomal glycerol phosphate acyltransferase, dihydroxyacetone phosphate acyltransferase, phosphatidate cytidylyltransferase, diacylglycerol acyltransferase and choline phosphotransferase, and of the soluble phosphatidate phosphohydrolase, were measured. 3. The soluble phosphatidate phosphohydrolase activity was higher in those rats fed on lard than in those fed on the starch diet. Choline phosphotransferase activity was higher in the rats fed on corn oil than in those fed on the starch diet. 4. The rate of hepatic glycerolipid synthesis was measured in vivo 1 min after injection of [1,3-3H]glycerol and [1-14C]palmitate into the portal veins. 5. The relative rate of phosphatidylcholine synthesis in vivo was increased after feeding with corn oil and the higher specific activity of choline phosphotransferase may contribute to this result. The equivalent rate of triacylglycerol synthesis was increased by feeding with lard rather than corn oil, and the increased activity of phosphatidate phosphohydrolase may partly explain this. The latter changes probably contribute to the increased concentration of triacylglycerol which other authors have observed in the livers and sera of animals fed on saturated and monounsaturated fats.

scholarly journals The activities of lipoprotein lipase and of enzymes involved in triacylglycerol synthesis in rat adipose tissue. Effects of starvation, dietary modification and of corticotropin injection

1981 ◽  
Vol 200 (2) ◽  
pp. 285-294 ◽  
Author(s):  
N Lawson ◽  
A D Pollard ◽  
R J Jennings ◽  
M I Gurr ◽  
D N Brindley
Keyword(s):  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Corn Oil ◽  
Diacylglycerol Acyltransferase ◽  
Dietary Modification ◽  
Dihydroxyacetone Phosphate ◽  
Glycerol Phosphate ◽  
Triacylglycerol Synthesis ◽  
Phosphatidate Phosphohydrolase ◽  
Starch Diet

1. The effects of dietary modification, including starvation, and of corticotropin injection on the activities of acyl-CoA synthetase, glycerol phosphate acyltransferase, dihydroxyacetone phosphate acyltransferase, phosphatidate phosphohydrolase, diacylglycerol acyltransferase and lipoprotein lipase were measured in adipose tissue. 2. Lipoprotein lipase activities in heart were increased and those in adipose tissue were decreased when rats were fed on diets enriched with corn oil or beef tallow rather than with sucrose or starch. The lipoprotein lipase activity was lower in the adipose tissue of rats fed on the sucrose rather than on the starch diet. 3. Rats fed on the beef tallow diet had slightly higher activities of the total glycerol phosphate acyltransferase in adipose tissue than did rats fed on the sucrose or starch diet. The diacylglycerol acyltransferase and the mitochondrial glycerol phosphate acyltransferase activities were higher for the rats fed on the tallow diet than for those fed on the corn-oil diet. 4. Starvation significantly decreased the activities of lipoprotein lipase (after 24 and 48 h), acyl-CoA synthetase (after 24 h) and of the mitochondrial glycerol phosphate acyltransferase and the N-ethylmaleimide-insensitive dihydroxyacetone phosphate acyltransferase (after 48 h) in adipose tissue. The activities of the microsomal glycerol phosphate acyltransferase, diacylglycerol acyltransferase and the soluble phosphatidate phosphohydrolase were not significantly changed after 24 or 48 h of starvation. 5. The activities of lipoprotein lipase and phosphatidate phosphohydrolase in adipose tissue were decreased 15 min after corticotropin was injected into rats during November to December. No statistically significant differences were found when these experiments were performed during March to September. These differences may be related to the seasonal variation in acute lipolytic responses. 6. These results are discussed in relation to the control of triacylglycerol synthesis and lipoprotein metabolism.

scholarly journals The glycerol phosphate, dihydroxyacetone phosphate and monoacylglycerol pathways of glycerolipid synthesis in rat adipose-tissue homogenates

1976 ◽  
Vol 160 (3) ◽  
pp. 693-700 ◽  
Author(s):  
P F Dodds ◽  
M I Gurr ◽  
D N Brindley
Keyword(s):  
Adipose Tissue ◽  
Dihydroxyacetone Phosphate ◽  
Glycerol Phosphate ◽  
Epididymal Fat ◽  
Tissue Homogenates ◽  
Glycerolipid Synthesis ◽  
Acyl Acceptors ◽  
Rat Adipose Tissue ◽  
Fat Pads

1. Fat-free homogenates from the epididymal fat-pads of rats were used to measure the rate of palmitate esterification with different substrates. The effectiveness of the acyl acceptors decreased in the order glycerol phosphate, dihydroxyacetone phosphate, 2-octadecenyl-glycerol and 2-hexadecylglycerol. 2. Glycerol phosphate and dihydroxyacetone phosphate inhibited their rates of esterification in a mutually competitive manner. 3. The esterification of glycerol phosphate was also inhibited in a partially competitive manner by 2-octadecenylglycerol and to a lesser extent by 2-hexadecylglycerol. However, glycerol phosphate did not inhibit the esterification of 2-octadecenylglycerol. 4. The esterification of dihydroxyacetone phosphate and 2-hexadecylglycerol was more sensitive to inhibition by clofenapate than was that of glycerol phosphate. Norfenfluramine was more effective in inhibiting the esterification of 2-hexadecylglycerol than that of glycerol phosphate or dihydroxyacetone phosphate. 5 It is concluded that rat adipose tissue can synthesize glycerolipids by three independent routes.

scholarly journals Neonatal nutritional programming impairs adiponectin effects on energy homeostasis in adult life of male rats

2018 ◽  
Vol 315 (1) ◽  
pp. E29-E37 ◽  
Author(s):  
Mariana Peduti Halah ◽  
Paula Beatriz Marangon ◽  
Jose Antunes-Rodrigues ◽  
Lucila L. K. Elias
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Weight Gain ◽  
Food Intake ◽  
White Adipose Tissue ◽  
Energy Homeostasis ◽  
Body Weight Gain ◽  
Adult Life ◽  
Male Rats ◽  
Nutritional Programming

Neonatal nutritional changes induce long-lasting effects on energy homeostasis. Adiponectin influences food intake and body weight. The aim of this study was to investigate the effects of neonatal nutritional programming on the central stimulation of adiponectin. Male Wistar rats were divided on postnatal (PN) day 3 in litters of 3 (small litter, SL), 10 (normal litter, NL), or 16 pups/dam (large litter, LL). We assessed body weight gain for 60 days, adiponectin concentration, and white adipose tissue weight. We examined the response of SL, NL, and LL rats on body weight gain, food intake, oxygen consumption (V̇o2), respiratory exchange ratio (RER), calorimetry, locomotor activity, phosphorylated-AMP-activated protein kinase (AMPK) expression in the hypothalamus, and uncoupling protein (UCP)-1 in the brown adipose tissue after central stimulus with adiponectin. After weaning, SL rats maintained higher body weight gain despite similar food intake compared with NL rats. LL rats showed lower body weight at weaning, with a catch up afterward and higher food intake. Both LL and SL groups had decreased plasma concentrations of adiponectin at PN60. SL rats had increased white adipose tissue. Central injection of adiponectin decreased body weight and food intake and increased V̇o2, RER, calorimetry, p-AMPK and UCP- 1 expression in NL rats, but it had no effect on SL and LL rats, compared with the respective vehicle groups. In conclusion, neonatal under- and overfeeding induced an increase in body weight gain in juvenile and early adult life. Unresponsiveness to central effects of adiponectin contributes to the imbalance of the energy homeostasis in adult life induced by neonatal nutritional programming.

Diurnal rhythms and effects of fasting and refeeding on rat adipose tissue lipoprotein lipase

1996 ◽  
Vol 271 (6) ◽  
pp. E1092-E1097 ◽  
Author(s):  
M. Bergo ◽  
G. Olivecrona ◽  
T. Olivecrona
Keyword(s):  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Specific Activity ◽  
Early Morning ◽  
Diurnal Rhythms ◽  
Mrna Levels ◽  
Short Term ◽  
Early Afternoon ◽  
Rat Adipose Tissue ◽  
Adipose Tissue Lipoprotein Lipase

The activity of lipoprotein lipase (LPL) in adipose tissue is modulated by changes in the nutritional status. We have measured LPL activity, mass, and mRNA levels in rat adipose tissue during normal feeding cycles, during short- and long-term fasting, and during refeeding after fasting. LPL activity displayed a diurnal rhythm. The activity was highest during the night and early morning, decreased to a minimum during the early afternoon, and then increased again. These changes corresponded to the feeding pattern. The increases and/or decreases resulted from changes in LPL synthetic rate compounded by posttranslational mechanisms. During short-term fasting, LPL specific activity decreased to < 30% of control. The specific activity was restored within 4 h by refeeding. On longer fasting, LPL mRNA decreased. This became significant from 36 h. On refeeding, it took 12 h to restore the mRNA levels, whereas tissue LPL activity and mass could not be fully restored by 36 h of refeeding. These data show that LPL activity during short-term fasting is regulated posttranscriptionally, which allows for quick upregulation after refeeding. On longer fasting, other mechanisms affecting LPL transcription and synthesis come into play, and upregulation after refeeding is slowed down.

scholarly journals Expression of leptin and β3-adrenergic receptors in rat adipose tissue in altered thyroid states

1997 ◽  
Vol 322 (1) ◽  
pp. 145-150 ◽  
Author(s):  
John N. FAIN ◽  
Elizabeth C. CORONEL ◽  
Michael J. BEAUCHAMP ◽  
Suleiman W. BAHOUTH
Keyword(s):  
Adipose Tissue ◽  
Adrenergic Receptor ◽  
Male Rats ◽  
Epididymal Adipose Tissue ◽  
Mrna Levels ◽  
Receptor Mrna ◽  
Cl 316,243 ◽  
Altered Thyroid ◽  
Rat Adipose Tissue ◽  
Receptor Mrnas

The level of leptin [the obese (ob) gene product] mRNA is markedly elevated in hypothyroid male rats. The administration of tri-iodothyronine (T3) to hypothyroid rats resulted in a 40% decrease in leptin mRNA at 8 h. This decrease in leptin mRNA was associated with a parallel decline in circulating leptin levels of about 50% at 24 h. Conversely, β3-adrenergic receptor mRNA levels were markedly decreased in epididymal adipose tissue from hypothyroid rats. T3 administration resulted in a 147% increase at 12 h in β3-adrenergic receptor mRNA. There was a corresponding increase due to T3 in the lipolytic response to the specific β3-adrenergic agonist CL 316,243 that paralleled the increase in β3-adrenergic receptor mRNA. T3-mediated changes in leptin and β3-adrenergic receptor mRNAs were blocked by cycloheximide, suggesting the involvement of short-lived proteins in these effects. The present results indicate that T3 has opposite effects to those of insulin on the white adipose tissue of rats with respect to leptin mRNA expression.

scholarly journals Effects of glucose and insulin on the activation of lipoprotin lipase and on protein-synthesis in rat adipose tissue

1980 ◽  
Vol 188 (1) ◽  
pp. 193-199 ◽  
Author(s):  
S M Parkin ◽  
K Walker ◽  
P Ashby ◽  
D S Robinson
Keyword(s):  
Protein Synthesis ◽  
Enzyme Activity ◽  
Adipose Tissue ◽  
Lipoprotein Lipase ◽  
Specific Activity ◽  
The Other ◽  
Lipoprotein Lipase Activity ◽  
Fat Bodies ◽  
Rat Adipose Tissue ◽  
Adipose Tissue Lipoprotein Lipase

Glucose, and certain sugars that can readily be converted to glucose 6-phosphate, bring about an activation of adipose-tissue lipoprotein lipase when epididymal fat-bodies from starved rats are incubated in the presence of cycloheximide. Other substrates do not support the activation. If the tissue is preincubated in the presence of cycloheximide for longer than 2h, the ability of added glucose to activate the enzyme is lost. On the other hand, the addition of glucose still brings about an increase in lipoprotein lipase activity after preincubation in the absence of cycloheximide for as long as 4h. The magnitude of the increase in enzyme activity brought about by the addition of glucose is increased when protein synthesis is stimulated during the preincubation period by insulin. The results are interpreted in terms of the existence in adipose tissue of a proenzyme pool of lipoprotein lipase that is normally maintained by protein synthesis and that is converted to complete enzyme of higher specific activity by a process that specifically requires glucose.

MEAL-EATING AND LIPOGENESIS IN VITRO OF RATS FED A LOW-PROTEIN DIET

1964 ◽  
Vol 42 (5) ◽  
pp. 665-670 ◽  
Author(s):  
J. R. Beaton ◽  
V. Feleki ◽  
A. J. Szlavko ◽  
J. A. F. Stevenson
Keyword(s):  
Adipose Tissue ◽  
Food Intake ◽  
Body Weight Gain ◽  
Liver Glycogen ◽  
Male Rats ◽  
Acetate Incorporation ◽  
Casein Diet ◽  
Low Protein ◽  
Daily Food

The response of male rats to the restriction of food intake to 2 hours each day for 14 to 16 days has been assessed by the measurement of food intakes, body weights, liver glycogen concentrations, and lipogenesis of adipose tissue (C14-acetate incorporation in vitro). The animals were fed either a 20% casein diet (controls) or an isocaloric 5% casein diet. As a consequence of meal-eating, and regardless of dietary protein level, the average daily food intake and body weight gain were decreased whereas the lipogenesis in vitro and liver glycogen concentration were increased in comparison with rats fed ad libitum,which is in agreement with earlier findings using normal diets. These observations suggest that the decreased body fat of rats fed a 5% casein diet is not a consequence of an impaired ability of adipose tissue to synthesize fat.

Exercise and the cAMP system in rat adipose tissue II. Nucleotide catabolism

1981 ◽  
Vol 50 (2) ◽  
pp. 255-258 ◽  
Author(s):  
W. K. Palmer ◽  
C. A. Kalina ◽  
T. A. Studney ◽  
L. B. Oscai
Keyword(s):  
Adipose Tissue ◽  
Exercise Training ◽  
Physical Training ◽  
Treadmill Running ◽  
Male Rats ◽  
Tetraacetic Acid ◽  
Phosphodiesterase Activity ◽  
Similar Extent ◽  
Camp System ◽  
Rat Adipose Tissue

In this study the effect of exercise training on the adenosine 3',5'-cyclic monophosphate (cAMP) system of rat adipose tissue has been investigated. The basal amount of cAMP for the exercising rats was 0.179 +/- 0.021 nmol/10(6) cells, the same value as for the controls. Phosphodiesterase activities (low and high Km) remained unaffected as a result of the program of treadmill running. Kinetic constants for the low- and high-Km phosphodiesterases revealed that the affinity of the enzymes for substrate (cAMP) was unaltered by physical training. Finally, ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid, possibly through its effect on calmodulin, stimulated or inhibited (depending on concentration) phosphodiesterase activity in the same direction and to a similar extent in extracts of adipose tissue from runners and controls. Taken together, these data clearly demonstrate the exercise training has no effect on the cAMP system of adipose tissue in male rats.

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