Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carbenoxolone slightly but significantly decreased the release of FFA from rat epididymal fat pads. The antilipolytic action of carbenoxolone was not blocked by 10(-3)M 3-isobutyl-1-methylxanthine, a potent inhibitor of phosphodiesterase. The findings suggest that carbenoxolone exerts its antilipolytic activity by acting on adenylate cyclase, thereby decreasing cyclic AMP concentrations and the activity of the hormone-sensitive lipase in adipose tissue.
 ...
PMID:Effect of carbenoxolone on lipolysis in rat adipose tissue. 2 44

Lipolytic activity was studied in brown and white adipose tissue of rats in vitro. 5-Hydroxy-tryptamine (5-HT), phenylephrine, noradrenaline, adrenaline and isoprenaline were used as adipokinetic agents. All stimulated lipolysis in brown adipose tissue, but 5-HT and phenyl-ephrine did not in white adipose tissue. A beta-blocking drug, propranolol, inhibited the stimulatory effect of the agents in both adipose tissues. However, an alpha-blocking drug, phentolamine, further increased the lipolysis induced by noradrenaline or adrenaline in brown adipose tissue and inhibited the effect of isoprenaline. In white adipose tissue, its action was to marginally decrease the effect of adrenaline and noradrenaline. Increase in the pH of the incubation medium stimulated FFA and glycerol release in brown adipose tissue, but not in the epididymal adipose tissue. This effect of pH on lipolysis was further enhanced by phentolamine and decreased by propranolol. Increase of lipolysis with pH was not seen with brown fat tissue from the reserpine-treated rats. These results show that brown adipose tissue of the rat has an alpha-receptor with inhibitory effects on lipolysis that is affected by alpha- or mixed-type adrenergic agonists, noradrenaline and adrenaline.
 ...
PMID:Differences in responsiveness to adipokinetic agents between white epididymal and brown interscapula adipose tissue from rats. 3 Aug 17

Gonadal hormones affect body composition, food intake, weight gain and serum lipids in numerous species including man. In this study, mature male Sprague-Dawley rats were castrated or sham-operated at 16 weeks of age. During the 6-week observation period with weekly records of food intake and weight gain, these parameters were significantly lower in the castrated group. The decrease in food intake in this group could not account for the difference in body weight between the groups, indicating a lower feed utilisation in the castrates. At sacrifice accessory reproductive organs, the levator ani muscle, thymus and adrenals were dissected for determination of organ weight and histology, revealing significant reductions in the accessory reproductive organs and levator ani of the castrates. The thymus was significantly heavier in the castrated animals. No differences were found in the adrenals. Two of the sham-operated animals had signs of accidental functional castration. The proportion of body cell mass and total lipid of the carcass was the same in both groups. Significant reductions in adipocyte weights were found in the epididymal depots of the castrated rats. Blood samples taken at sacrifice in pentobarbital anaesthesia were analysed for glucose, insulin, triglycerides, cholesterol, FFA, glycerol and protein. Statistically significant reductions in triglycerides and protein were recorded in the castrated animals without any significant changes in the other parameters studied. The results are discussed with reference to the age of castration and the importance of the reduced food intake in castrated animals.
 ...
PMID:The effects of castration on body composition, adipose tissue cellularity and lipid and carbohydrate metabolism in adult male rats. 94 53

Lipoprotein lipase (LPL) is an enzyme found in adipose tissue that is important in the hydrolysis of triglyceride rich lipoproteins, and in the uptake of FFA lipid into the adipocyte. To examine the effects of glucocorticoids on adipose tissue LPL, male Sprague-Dawley rats were injected with dexamethasone (1 mg/kg) every other day for 10 days, followed by measurement of LPL in epididymal adipose tissue. Compared to sham-injected controls, heparin-releasable LPL activity and LPL mass in the dexamethasone-treated rats were 44% and 62% of those in control rats, respectively. Adipocytes were prepared from the fat pads and pulse labeled with [35S]methionine, demonstrating a decrease in the LPL synthetic rate in the treated rats to 57% of the rate in control rats. In addition, LPL mRNA was quantitated by Northern blotting, demonstrating a decrease in LPL mRNA in the dexamethasone-treated rats. A simultaneous decrease in the message for gamma-actin was also noted. To examine the effects of dexamethasone on LPL in vitro, adipocytes were prepared from normal rats and treated with dexamethasone for 24 h in vitro. Dexamethasone decreased heparin-releasable LPL activity in cultured adipocytes to 40 +/- 6% of the control value (P less than 0.01). This decrease in LPL activity was accompanied by a decrease in the LPL synthetic rate using [35S]methionine labeling, to 33% of the control value, and no specific change in LPL turnover or secretion. In addition, dexamethasone added to adipocytes decreased LPL mRNA levels. Because the combination of insulin plus dexamethasone has been shown to yield synergistic increases in LPL in adipose tissue pieces, insulin was added to isolated adipocytes in combination with dexamethasone. Whereas insulin and dexamethasone individually had opposite effects on LPL, the combination of insulin plus dexamethasone resulted in no change in any aspect of LPL gene expression. Thus, dexamethasone resulted in a decrease in adipocyte LPL mRNA levels both when added to cultured adipocytes in vitro as well as when injected into rats. This decreased LPL mRNA level yielded corresponding changes in the LPL synthetic rate and LPL activity.
 ...
PMID:The regulation of lipoprotein lipase gene expression by dexamethasone in isolated rat adipocytes. 154 42

Male Sprague-Dawley rats displayed significantly higher rates of triglyceride/fatty acid (TG/FFA) substrate cycling in subcutaneous, perigenital, and mesenteric white adipose tissue, compared to females. To investigate possible regulation via androgens and estrogens, male rats were treated with the androgen antagonist, cyproterone acetate (10 mg daily in subcutaneous injections), or estradiol polyphosphate (0.3 mg intramuscularly, given as a single dose). Estradiol treatment did not affect TG/FFA cycling. Treatment with cyproterone acetate significantly decreased TG/FFA cycling in perigenital (epididymal) tissue. This effect could however largely be ascribed to concomitant inhibition of food intake by cyproterone acetate. The effects of cyproterone acetate on the two axes of TG/FFA cycling (lipolysis and re-esterification) were further studied in vitro. Norepinephrine-stimulated glycerol release from perigenital adipocytes was inhibited, whereas activities of esterification enzymes (GPAT and PPH) was essentially unaffected. We conclude that androgens seem to affect TG/FFA cycling indirectly via the lipolytic axis.
 ...
PMID:Sex difference in triglyceride/fatty acid substrate cycling of rat adipose tissue: indirect regulation by androgens. 183 7

Previously, the antilipolytic effect of prostaglandin E2 (PGE2) has been investigated in conventional adipocyte incubations. To define the effect of PGE2 on lipolysis more clearly, isolated epididymal adipocytes were studied with the perifusion system. PGE2 inhibited isoproterenol (100 nM)- and theophylline (1 mM)-stimulated lipolysis in a concentration-dependent manner in both the perifusion system and conventional incubations. However, the half-maximally inhibitory concentration (ED50) of PGE2 on isoproterenol-induced lipolysis was about 0.4 nM in the perifusion system, whereas the ED50 was 8 nM in the static adipocyte incubations. The ED50 values of PGE2 on theophylline-induced lipolysis were 0.8 nM (perifusion) and 5 nM (incubation), respectively. Thus, the sensitivity of stimulated lipolysis to PGE2 was about 10 times higher in the perifusion system than in conventional adipocyte incubations. In addition, the maximal antilipolytic effect of PGE2 was greater in the perifusion system. At a concentration of 100 nM PGE2 inhibited theophylline-induced lipolysis by 82 +/- 5% in adipocyte incubations, whereas lipolysis was inhibited by 100 +/- 3.5% in the perifusion system (P less than 0.05). When lipolysis was stimulated by isoproterenol the maximal antilipolytic effect of PGE2 was an inhibition of 90 +/- 2.5% in the perifusion system and 55 +/- 5% in adipocyte incubations (P less than 0.05). Moreover, the maximal antilipolytic effect was obtained at a PGE2 concentration of 20 nM in the perifusion system, but at a concentration of 100 nM in static incubations. The release of immunoreactive PGE2 from adipocytes was measured by RIA. In the perifusion system no PGE2 could be detected in the effluent under basal conditions; however, during exposure to 100 nM isoproterenol a small amount of PGE2 was detected (3-4.5 pg/10(6) cells X min). Exogenous PGE2 was almost totally (90%) recovered in the effluent. In adipocyte incubations basal PGE2 production was 103 +/- 22 pg/10(6) cells X 60 min, whereas both isoproterenol and theophylline increased these amounts of PGE2 2-fold (P less than 0.01). It is concluded that exogenous PGE2 has pronounced antilipolytic properties at very low concentrations (subnanomolar) in perifused adipocytes. The reduced sensitivity and maximal responsiveness of PGE2 in static incubations may be related to accumulation of FFA and endogenous PGs, which may partially obscure the interaction of exogenous PGE2 with the adenylate cyclase complex.
 ...
PMID:Antilipolytic effect of prostaglandin E2 in perifused rat adipocytes. 330 32

Arginine vasopressin (AVP) action on the lipolysis, both the basic and induced with noradrenaline, was studied in adipocytes isolated from epididymal fat pads of Wistar rats sacrificed after 24-hr food deprivation. Adipocytes were exposed to hormones for 10 or 15 min. Lipolysis was estimated by measuring FFA release. AVP alone in relatively small concentrations (8 X 10(-9) M and 8 X 10(-11) M) stimulated FFA release by 39.6% and 56.3%, resp. Higher concentrations (8 X 10(-7) M) exerted no effect. Having been added to noradrenaline, however, AVP in concentrations 8 X 10(-7) M and 8 X 10(-9) M decreased lipolytic effect of the former, although the decrease was statistically insignificant. Whether the activating effect of AVP is due to the stimulation of lipolysis or to changes in membrane permeability for FFA, is to be elucidated.
 ...
PMID:[Stimulating effect of arginine vasopressin on the release of free fatty acids by isolated rat adipose cells]. 360 81

There is a 'futile' cycle of unknown significance operating at a very rapid rate (about 40 percent that of the total central fat droplet's daily turnover rate) in white adipose tissue of normal mice. The futile cycle may be measured and studied because it occurs in a region of the adipose tissue that has poor anatomical contact with the capillaries coupled with a high affinity of the adipocytes, plasma membranes for the FFA in the ECF. The cycle is drastically inhibited in mice bearing the Ehrlich ascites carcinoma, a transplantable tumor; the inhibition is associated with a 20-fold increase in the FFA pool size of the epididymal fat pad (measured directly) and a 70 percent reduction in the TGFA pool that is involved in the cycle (estimated indirectly from kinetic measurements). However, the mass of TGFA in the central lipid droplet was being conserved in the tumor-bearing mice during this study. The TGFA pool involved in the cycle represents only about 1 percent of the total adipose tissue TGFA. The relation of this futile cycle to adipose TGFA turnover, plasma FFA turnover and oxidation to CO2, dietary sources of TGFA, and the loss (and preservation) of body fat in cancer-bearing animals was considered in terms of a simple model. Although the significance of the altered futile cycle is unknown, the new approach described here, coupled with other quantitative tracer and non-tracer measurements, may prove useful in understanding factors that lead to obesity or body fat loss.
 ...
PMID:In vivo tracer studies of perturbed fatty acid transport and metabolism in adipose tissue. 406 21

Guinea pigs have varying plasma triglyceride concentrations ranging from 28 to 1392 mg/dl, with relatively uniform plasma cholesterol and phospholipid levels. To understand why the animals exhibit such wide variations of plasma triglyceride concentrations, we have explored the triglyceride hydrolyzing system by measuring tissue lipoprotein lipase activities and plasma activator for the enzyme. Lipoprotein lipase activities of epididymal adipose tissue of these animals were 759 +/- 117 (mean +/- SE) n moles FFA X min-1 X g wet tissue-1, markedly low compared with those of rats. There were no relationships between plasma triglyceride concentrations and tissue lipase activities. Plasma activator for lipoprotein lipase was lacking in this animal. Guinea pigs with ascorbic acid deficiency for 2 weeks also showed marked variations of plasma triglyceride concentrations, without any changes in tissue lipoprotein lipase activities. Low adipose tissue lipoprotein lipase activities with deficient plasma activator for the enzyme suggest that the lipoprotein lipase-mediated triglyceride degradation could be impaired in this animal, and this may account for the marked variation of plasma triglyceride concentrations.
 ...
PMID:Wide variations of plasma triglyceride concentrations in guinea pigs. 652 15

Partially purified human GH was subjected to chromatogrphy on DEAE-cellulose to yield a preparation that lacked in vitro lipolytic activity in the rat epididymal fat pad even in the presence of dexamethasone. Release of both glycerol and FFA was examined after a 4-h incubation and was found to be unaffected by concentrations of GH as high as 0.1 mg/ml incubation medium. The lipolytic activity of the original partially purified GH was detected in an acidic fraction from the DEAE-cellulose chromatography. Similar results were obtained with bovine GH. Adipose tissue from rats fed Purina rat chow was more responsive to the lipolytic factor than tissue from rats fed a high sucrose, fat-free diet.
 ...
PMID:Absence of in vitro dexamethasone-dependent lipolytic activity from highly purified growth hormone. 739 77


1 2 3 Next >>