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.

Exercise and the cAMP system in rat adipose tissue. I. Lipid mobilization

1981 ◽  
Vol 50 (2) ◽  
pp. 250-254 ◽  
Author(s):  
L. B. Oscai ◽  
R. A. Caruso ◽  
A. C. Wergeles ◽  
W. K. Palmer
Keyword(s):  
Adipose Tissue ◽  
Binding Capacity ◽  
Exercise Program ◽  
Treadmill Running ◽  
Hormone Sensitive Lipase ◽  
Male Rats ◽  
Tissue Slices ◽  
Hormone Sensitive ◽  
Camp System ◽  
Rat Adipose Tissue

Protein kinase (PK) and hormone-sensitive lipase (HSL) were measured at rest in adipose tissue of untrained male rats and in that of animals subjected to a strenuous program of treadmill running. Total amounts of PK activity (decreased from 860 +/- 104 to 474 +/- 53 pmol.min-1. (10(6) cells)-1 (P less than 0.01) as a result of exercise training. At the same time, binding capacity for adenosine 3',5'-cyclic monophosphate (cAMP) was elevated in the runners. These data suggest a functional loss in catalytic activity without a loss in binding capacity. In addition, the results provide evidence that the capacity of PK to activate HSL is reduced in adipocytes of physically trained rats. HSL activity was measured in both adipose tissue slices and isolated adipocytes. The results show that the levels of activity of HSL did not increase as a result of the running program. These results provide evidence that the lipolytic capacity of adipocytes of normal untrained male 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 HSL activity.

scholarly journals Interleukin-6 mediated exercise-induced alleviation of adiposity and hepatic steatosis in mice

2021 ◽  
Vol 9 (1) ◽  
pp. e001431
Author(s):  
Long Li ◽  
Caoxin Huang ◽  
Hongyan Yin ◽  
Xiaofang Zhang ◽  
Dongmei Wang ◽  
...  
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Exercise Training ◽  
Hepatic Steatosis ◽  
Interleukin 6 ◽  
Body Weight Gain ◽  
Treadmill Running ◽  
Alcoholic Fatty Liver ◽  
Fat Accumulation ◽  
Ppar Γ

IntroductionExercise training has been shown to be the most effective strategy to combat obesity and non-alcoholic fatty liver disease. However, exercise promotes loss of adipose tissue mass and improves obesity-related hepatic steatosis through mechanisms that remain obscure.Research design and methodsTo study the role of interleukin-6 (IL-6) in high-fat diet (HFD)-induced adiposity and hepatic steatosis during treadmill running, IL-6 knockout (IL-6 KO) mice and wild-type (WT) mice were randomly divided into lean, obese (fed a HFD) and trained obese groups (fed a HFD and exercise trained).ResultsAfter 20 weeks of HFD feeding and 8 weeks of treadmill running, we found that exercise obviously reduced HFD-induced body weight gain, inhibited visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) expansion and almost completely reversed obesity-related intrahepatic fat accumulation in WT mice. However, IL-6 knockout (IL-6 KO) mice are refractory to the benefits of treadmill training on body weight, VAT and SAT mass elevation, and hepatic steatosis. Moreover, a panel of lipolytic-related and thermogenic-related genes, including ATGL, HSL and PGC-1α, was upregulated in the VAT and SAT of WT mice that received exercise training compared with untrained mice, which was not observed in IL-6 KO mice. In addition, exercise training resulted in a significant inhibition of hepatic peroxisome proliferator-activated receptor gamma (PPAR-γ) expression in WT mice, and these effects were not noted in IL-6 KO mice.ConclusionThese results revealed that IL-6 is involved in the prevention of obesity and hepatic fat accumulation during exercise training. The mechanisms underlying these antiobesity effects may be associated with enhanced lipolysis and thermogenesis in white adipose tissue. The improvement in hepatic steatosis by exercise training may benefit from the marked inhibition of PPAR-γ expression by IL-6.

scholarly journals Exercise training enhances white adipose tissue metabolism in rats selectively bred for low- or high-endurance running capacity

2013 ◽  
Vol 305 (3) ◽  
pp. E429-E438 ◽  
Author(s):  
Erin J. Stephenson ◽  
Sarah J. Lessard ◽  
Donato A. Rivas ◽  
Matthew J. Watt ◽  
Ben B. Yaspelkis ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Exercise Training ◽  
White Adipose Tissue ◽  
Citrate Synthase ◽  
Mitochondrial Protein ◽  
Treadmill Running ◽  
Endurance Running ◽  
Insulin Resistant ◽  
Disease States ◽  
Hcr Model

Impaired visceral white adipose tissue (WAT) metabolism has been implicated in the pathogenesis of several lifestyle-related disease states, with diminished expression of several WAT mitochondrial genes reported in both insulin-resistant humans and rodents. We have used rat models selectively bred for low- (LCR) or high-intrinsic running capacity (HCR) that present simultaneously with divergent metabolic phenotypes to test the hypothesis that oxidative enzyme expression is reduced in epididymal WAT from LCR animals. Based on this assumption, we further hypothesized that short-term exercise training (6 wk of treadmill running) would ameliorate this deficit. Approximately 22-wk-old rats (generation 22) were studied. In untrained rats, the abundance of mitochondrial respiratory complexes I–V, citrate synthase (CS), and PGC-1 was similar for both phenotypes, although CS activity was greater than 50% in HCR ( P = 0.09). Exercise training increased CS activity in both phenotypes but did not alter mitochondrial protein content. Training increased the expression and phosphorylation of proteins with roles in β-adrenergic signaling, including β3-adrenergic receptor (16% increase in LCR; P < 0.05), NOR1 (24% decrease in LCR, 21% decrease in HCR; P < 0.05), phospho-ATGL (25% increase in HCR; P < 0.05), perilipin (25% increase in HCR; P < 0.05), CGI-58 (15% increase in LCR; P < 0.05), and GLUT4 (16% increase in HCR; P < 0.0001). A training effect was also observed for phospho-p38 MAPK (12% decrease in LCR, 20% decrease in HCR; P < 0.05) and phospho-JNK (29% increase in LCR, 20% increase in HCR; P < 0.05). We conclude that in the LCR-HCR model system, mitochondrial protein expression in WAT is not affected by intrinsic running capacity or exercise training. However, training does induce alterations in the activity and expression of several proteins that are essential to the intracellular regulation of WAT metabolism.

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 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.

Short-term exercise training early in life restores deficits in pancreatic β-cell mass associated with growth restriction in adult male rats

2011 ◽  
Vol 301 (5) ◽  
pp. E931-E940 ◽  
Author(s):  
Rhianna C. Laker ◽  
Linda A. Gallo ◽  
Mary E. Wlodek ◽  
Andrew L. Siebel ◽  
Glenn D. Wadley ◽  
...  
Keyword(s):  
Exercise Training ◽  
Glucose Tolerance ◽  
Adult Male ◽  
Early Life ◽  
Cell Mass ◽  
Growth Restriction ◽  
Treadmill Running ◽  
Male Rats ◽  
Pancreatic Β Cell ◽  
Β Cell

Fetal growth restriction is associated with reduced pancreatic β-cell mass, contributing to impaired glucose tolerance and diabetes. Exercise training increases β-cell mass in animals with diabetes and has long-lasting metabolic benefits in rodents and humans. We studied the effect of exercise training on islet and β-cell morphology and plasma insulin and glucose, following an intraperitoneal glucose tolerance test (IPGTT) in juvenile and adult male Wistar-Kyoto rats born small. Bilateral uterine vessel ligation performed on day 18 of pregnancy resulted in Restricted offspring born small compared with sham-operated Controls and also sham-operated Reduced litter offspring that had their litter size reduced to five pups at birth. Restricted, Control, and Reduced litter offspring remained sedentary or underwent treadmill running from 5 to 9 or 20 to 24 wk of age. Early life exercise increased relative islet surface area and β-cell mass across all groups at 9 wk, partially restoring the 60–68% deficit ( P < 0.05) in Restricted offspring. Remarkably, despite no further exercise training after 9 wk, β-cell mass was restored in Restricted at 24 wk, while sedentary littermates retained a 45% deficit ( P = 0.05) in relative β-cell mass. Later exercise training also restored Restricted β-cell mass to Control levels. In conclusion, early life exercise training in rats born small restored β-cell mass in adulthood and may have beneficial consequences for later metabolic health and disease.

Effects Of Aging And Exercise Training On Alpha-adrenergic Vasomotor Responses Of Rat Adipose Tissue Arterioles

2010 ◽  
Vol 42 ◽  
pp. 1 ◽  
Author(s):  
Robert T. Davis ◽  
Danielle J. McCullough ◽  
James M. Dominguez ◽  
Bradley J. Behnke
Keyword(s):  
Adipose Tissue ◽  
Exercise Training ◽  
Vasomotor Responses ◽  
Rat Adipose Tissue ◽  
Effects Of Aging

Exercise early in life in rats born small does not normalize reductions in skeletal muscle PGC-1α in adulthood

2012 ◽  
Vol 302 (10) ◽  
pp. E1221-E1230 ◽  
Author(s):  
Rhianna C. Laker ◽  
Mary E. Wlodek ◽  
Glenn D. Wadley ◽  
Linda A. Gallo ◽  
Peter J. Meikle ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Mitochondrial Biogenesis ◽  
Cell Mass ◽  
Treadmill Running ◽  
Male Rats ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Adult Skeletal Muscle ◽  
Early Exercise

We have previously shown that 4 wk of exercise training early in life normalizes the otherwise greatly reduced pancreatic β-cell mass in adult male rats born small. The aim of the current study was to determine whether a similar normalization in adulthood of reduced skeletal muscle mitochondrial biogenesis markers and alterations in skeletal muscle lipids of growth-restricted male rats occurs following early exercise training. Bilateral uterine vessel ligation performed on day 18 of gestation resulted in Restricted offspring born small ( P < 0.05) compared with both sham-operated Controls and a sham-operated Reduced litter group. Offspring remained sedentary or underwent treadmill running from 5–9 (early exercise) or 20–24 (later exercise) wk of age. At 24 wk of age, Restricted and Reduced litter offspring had lower ( P < 0.05) skeletal muscle peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) protein expression compared with Control offspring. Early exercise training had the expected effect of increasing skeletal muscle markers of mitochondrial biogenesis, but, at this early age (9 wk), there was no deficit in Restricted and Reduced litter skeletal muscle mitochondrial biogenesis. Unlike our previous observations in pancreatic β-cell mass, there was no “reprogramming” effect of early exercise on adult skeletal muscle such that PGC-1α was lower in adult Restricted and Reduced litter offspring irrespective of exercise training. Later exercise training increased mitochondrial biogenesis in all groups. In conclusion, although the response to exercise training remains intact, early exercise training in rats born small does not have a reprogramming effect to prevent deficits in skeletal muscle markers of mitochondrial biogenesis in adulthood.

Exercise-inducible factors to activate lipolysis in adipocytes

2013 ◽  
Vol 115 (2) ◽  
pp. 260-267 ◽  
Author(s):  
Takeshi Hashimoto ◽  
Koji Sato ◽  
Motoyuki Iemitsu
Keyword(s):  
Exercise Training ◽  
Metabolic Diseases ◽  
Lipolytic Activity ◽  
Treadmill Running ◽  
Hormone Sensitive Lipase ◽  
Male Rats ◽  
No Donor ◽  
Protein Levels ◽  
Epididymal Fat ◽  
Fatty Acid Release

We examined the effects of exercise training on the levels of lipid droplet (LD)-associated and mitochondria-related proteins in diet-induced obese (DIO) rats. Furthermore, we assessed putative factors induced by exercise to activate lipolysis in differentiated 3T3-L1 adipocytes. DIO Wistar male rats (age 20 wk) were divided into sedentary control (SED, n = 7) and exercise training (EX, n = 7) groups. EX animals were subjected to treadmill running (25 m/min, 1 h/day, 5 days/wk) for 6 wk. Epididymal fat was dissected and used for protein analyses. 3T3-L1 adipocytes were incubated with media containing hydrogen peroxide (H2O2), sodium-lactate, caffeine, AICAR, or SNAP (NO donor) for 6 h, or 1 mM H2O2 for 15 min, followed by incubation with normal media for up to 24 h total. Protein expression levels and lipolytic activities were biochemically assayed. Epididymal fat significantly decreased in EX animals compared with SED animals. Levels of cytochrome c oxidase (COx), perilipin, hormone sensitive lipase (HSL), and adipose triglyceride lipase (ATGL) proteins in epididymal fat pads of EX animals were significantly increased compared with those in SED animals. In 3T3-L1 cells, glycerol or fatty acid release was significantly increased by all treatments. Lactate or SNAP significantly increased PGC-1α expression, and H2O2 significantly increased COx protein levels compared with controls. Expression of perilipin, HSL, ATGL, or comparative gene identification (CGI)-58 was significantly increased by all treatments. By increasing lipolytic activity in adipocytes, the exercise-inducible factors are attractive therapeutic effectors against LD-associated metabolic diseases.

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