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

This study was undertaken to establish the time sequence of lipogenic changes in adipose tissue of rats when converted from ad libitum feeding to meal-eating. Rats were fed a high carbohydrate diet 2 hours/day for 0 to 10 days (meal-eating). The high speed supernatant fraction from homogenized epididymal fat pads was assayed for citrate cleavage enzyme, acetyl CoA carboxylase, fatty acid synthetase and malic enzyme activities. The effects of meal-feeding on in vitro and in vivo rates of fatty acid synthesis in adipose tissue as well as the amounts of glycogen deposited in the adipose tissue were measured. During the first 10 days of meal-feeding, the lipogenic enzyme activities were actually decreased or unchanged in the meal-fed rats but during this time the in vitro and in vivo rates of fatty acid synthesis were progressively increased in the meal-fed rats. Glycogen levels in the adipose tissue of meal-fed rats were greater than the levels in the nibblers. The initial hyperlipogenesis observed in the meal-fed rat appears to be due to changes in substrate uptake by the adipose tissue and/or to alterations in enzyme activation in the adipose tissue rather than to changes in the quantity of enzyme present in the tissue.
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PMID:Time sequence of lipogenic changes in adipose tissue of rats when converted from ad libitum feeding to meal-eating. 0 38

The plasma level of free fatty acids (FFA) in adrenalectomized rats increases by 50% after treatment with aldosterone (2 microng/100 g rat). Lipolytic activity in peripheral fat tissue is lowered after adrenalectomy and doubles after in vivo administration of aldosterone to adrenalectomized rats (measured as free fatty acid release in vitro from epididymal fat tissue). Lypolysis of adipose tissue stimulated by the in vitro presence of ACTH also increases after in vivo administration of aldosterone. Incorporation of intravenously administered label from U-14C-palmitate into total extractable lipid of renal tissue is augmented 3 h after aldosterone administration to adrenalectomized rats, while no increase of the radioactivity is observed in total lipid from liver tissue. Treatment with aldosterone does not affect the total lipid content of kidney or liver in adrenalectomized rats. The oxygen consumption rate of kidney cortex slices with lactate, beta-hydroxybuterate or acetoacetate as substrates is lowered after in vivo administration of aldosterone to adrenalectomized rats. With slccinate, however, the respiratory rate of kidney slices increases after aldosterone treatment of adrenalectomized rats, the ouabain-sensitive respiration being more affected than the ouabain-insensitive respiration. An interpretation of the O2 consumption data implicating competition of lipid metabolism for CoA-SH is discussed.
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PMID:Effects of aldosterone on lipid metabolism and renal oxygen consumption in the rat. 55 89

1. Enzyme activities (units/g wet wt.) were determined in the caput and cauda epididymidis and in epididymal spermatozoa of the rat. 2. The activity of most enzymes in the cauda was between 50 and 100% of that in the caput, except that ATP citrate lyase was barely detectable in the cauda. 3. Spermatozoa, unlike epididymal tissue, contained sorbitol dehydrogenase but lacked ATP citrate lyase. NADP+-malate dehydrogenase, mitochondrial glycerol 3-phosphate dehydrogenase, succinate dehydrogenase, carnitine acetyltransferase and citrate synthase were 5 to 400 times as active in spermatozoa as in epididymal tissue. 4. 2-Oxoglutarate dehydrogenase was the least active member of the tricarboxylic acid cycle in all tissues and most closely matched the measured flux through the cycle. 5. The concentrations of hydroxyacyl-CoA dehydrogenase and carnitine palmitoyltransferase were equivalent to the more active enzymes of the tricarboxylic acid cycle, indicating the capacity for extensive lipid oxidation, and the presence of 3-hydroxybutyrate dehydrogenase suggests that these tissues can also oxidize ketone bodies. 6. Transfer of reducing equivalents from cytoplasm to mitochondrion is unlikely to occur by means of the glycerol phosphate cycle because mitochondrial glycerol 3-phosphate dehydrogenase is relatively inactive in epididymal tissue, whereas the cytoplasmic enzyme has little activity in spermatozoa, but transfer may be accomplished by the malate-aspartate shuttle. 7. Transfer of acetyl units from mitochondrion to cytoplasm could be effected by the pyruvate-malate cycle in the caput of androgen-maintained rats, but not in the other tissues because of the low activity of ATP citrate lyase. Acetyl unit transfer could take place via acetylcarnitine, mediated by carnitine acetyltransferase. 8. Castration resulted in a decrease in the concentration of nearly all enzymes, although subsequent administration of testosterone restored concentrations to values similar to those in animals maintained by endogenous androgen. The extent to which enzyme concentration was changed by an alteration in androgen status was highly variable, but was most marked in the case of pyruvate carboxylase.
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PMID:Activity and androgenic control of enzymes associated with the tricarboxylic acid cycle, lipid oxidation and mitochondrial shuttles in the epididymis and epididymal spermatozoa of the rat. 72 83

Fat cells isolated from rat epididymal adipose tissue were incubated with albumin-bound [14C]palmitate. Incorporation of 14C into 14CO2 and glycerides was measured. Some evidence is presented to suggest that the exogenous palmitate pool is in isotopic equilibrium with intracellular precursors for these metabolic processes. Precautions were taken to minimize dilution of the exogenous palmitate pool by fatty acids released from the cells. 14CO2 production from [1-14C]palmitate was 3 times that from [16-14C]palmitate. Octanoate increased this differential oxidation of palmitate carbons and also inhibited palmitate oxidation without similarly affecting esterification. Glucose increases palmitate esterification in cells from fed or starved rats. Insulin potentiated this effect of glucose. Glucose influenced palmitate oxidation in a more complex manner, dependent upon the glucose concentration. Both the observation that esterification constitutes 99% of the metabolic flux of fatty acid and the manner in which glucose, insulin, or starvation influence palmitate esterification and oxidation suggested that factors controlling esterification may alter oxidation as a secondary effect, but not vice versa. It is suggested that oxidation and esterification compete for a single intracellular precursor, possibly extramitochondrial long chain fatty acyl CoA.
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PMID:Factors affecting fatty acid oxidation in fat cells isolated from rat white adipose tissue. 96 42

The purpose of the work was to establish the eventual "metabolic toxicity" of pesticide-contaminated diets in the Rat. The liver metabolic response to various stimuli was compared in dithiocarbamate-fed animals and in non-contaminated ones. 112 weanling male Wistar CF rats were fed, during 15 days, with a demi-synthetic control diet. They were then divided into 4 lots:--the control group C, which went on to receive the same diet,--the nabame group N, the diet of which was supplemented with 275 ppm of the dithiocarbamate;--the thirame groupe R, receiving the control diet + 600 ppm thirame;--the zineb groupe Z, given the control diet + 3 600 ppm Zineb. The animals were fed with these diets during 14 days, their dithiocarbamate intake thus averaging 1/20 th of the per os LD 50/rat/day. At the end of this 2-week period, each of the 4 groups was divided into 4 sub-groups, all the animals were fasted overnight, then sacrified:--after no other treatment (sub-groups T);--30 minutes after an i.p. injection of 2.6 g/kg glucose (G);--after having been forced to walk in a restraint wheel for 50 minutes/hr during the 18 hrs of the night fast (sub-groups W);--after a 90 minutes exposure in a cold room (F). The weights of the animals, of their liver, heart, kidneys, adrenals and epididymal pads were recorded. In their liver, the following compounds were determined: water, proteins, total lipids, triglycerides, long-chain acyl-CoA, non-esterified fatty acids, total cholesterol, glycogen, glucose, alpha-glycerophosphate. The thirame rats had a lower food intake than the others and the smallest body weight, but their relative liver and kidneys weights were the highest. The nabame animals did not differ from the control ones but the zineb rats had the lightest epididymal fat pads. The primary effects of the dithiocarbamate diets on liver metabolism were apparently not the same in the 3 groups compared to the control ones: nabame and thirame increased glycogen, thirame increased the lipid compounds: long-chain actyl-CoA and triglycerides, where as zineb feeding resulted in an increase of glucose concentration and in a decrease of triglycerides and total lipids. Muscular exercise, or cold exposure, had the following effects compared to those they had in the control group: a greater glucose utilization in the nabame and thirame rats, a smaller glycogen and glucose utilization, associated with an increase of alpha-glycerophosphate, in the zineb animals. These results were considered altogether with those obtained in a previous paper by the same authors, which concerned liver ketone bodies and adenine nucleotides changes after the same experimental conditions, and it was concluded that the 3 dithiocarbamates actually had a common effect on rat metabolism: they all impaired glucose utilization by the liver. Also, fat mobilization from peripheral depots was shown to occur in the 3 experimental groups, resulting in liver fatty acid oxidation in the nabame and zineb rats, and in liver steatosis for the thirame ones...
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PMID:[Short term effects of diets with high levels of dithiocarbamates on carbohydrate and lipid metabolism of rat liver]. 97 Aug 34

The free acids of the plasma lipid-lowering agents, halofenate and clofibrate inhibited the incorporation of radioactive glucose and pyruvate into fatty acids of isolated adipocytes prepared from rat epididymal fat pads. The concentration which inhibited fatty acid synthesis was dependent on the bovine serum albumin concentration in the incubation. The 50 per cent inhibitory concentration of the free acid of halofenate in 1 per cent, 2 percent and 4 per cent albumin was 0.9 mM, 2.3 MM and 4.4 mM, respectively. The potency of clofibrate was also lowered by increasing the albumin concentration. These compounds inhibited the uptake of both [14C]glucose and [14C]pyruvate to the same degree as the incorporation of these substrates into fatty acids. However, the drugs either had no effect on , or stimulated the uptake of palmitate by the cells. Leucine accumulation by the adipocytes was unaffected by halofenate (free acid) and inhibited by clofibrate (free acid). A comparison of these agents with (minus)-hydroxycitrate, kynurenate and cerulenin (inhibitors of ATP-citrate lyase, acetyl CoA carboxylase and fatty acid synthetase, respectively) on the oxidation of pyruvate suggested that they inhibited pyruvate metabolism at or near the enzyme, pyruvate dehydrogenase.
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PMID:Effect of halofenate and clofibrate on lipid synthesis in rat adipocytes. 112 Jan 40

Rat epididymal fat-pad extracts have previously been shown to contain an insulin-stimulated acetyl-CoA carboxylase kinase, which is co-eluted from Mono Q ion-exchange chromatography with a potent inhibitor of acetyl-CoA carboxylase [Borthwick, Edgell & Denton (1990) Biochem. J. 270, 795-801]. A variety of tests, including reactivity with thiol reagents, identify this inhibitor as CoA. Inhibition requires the presence of MgATP, but is independent of any phosphorylation of the enzyme. The effect is complete in about 5 min and is associated with depolymerization of acetyl-CoA carboxylase. Half-maximal inhibition is observed at about 40 nM-CoA. The inhibitory effects of CoA can be partially reversed by incubation with citrate and more fully overcome by treatment of the enzyme with the insulin-stimulated acetyl-CoA carboxylase kinase.
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PMID:Coenzyme A is a potent inhibitor of acetyl-CoA carboxylase from rat epididymal fat-pads. 134 28

Enzyme activities related to fatty acid synthesis were determined in liver extracts of rats treated with thioacetamide (TAM) for 8 weeks. Lipogenesis and cholesterogenesis in vivo were evaluated both in liver and in epididymal adipose tissue. The enzymatic activities of ATP-citrate lyase, acetyl CoA carboxylase, fatty acid synthetase, glycerol kinase and NAD-kinase decrease progressively when TAM was chronically administered. However, in the same experimental conditions malic enzyme and other NADP-enzymes were noticeably increased. This increase can be related to an excess of NADPH production necessary for detoxification rather than for lipogenesis. The rate of in vivo incorporation of 3H2O into non-saponifiable fraction in liver showed an increase in the acute phase (1-3 days) of TAM-treatment. In the chronic phase of TAM intoxication this rate returned to values close to normality. The rate of in vivo incorporation of 3H2O to fatty acid fraction increased in the liver during the acute phase of TAM-treatment and showed a sharp decrease during the subacute and chronic phases of the intoxication. At the end of the 60-day period of TAM-treatment, the radioactivity incorporated into fatty acids was significantly lowered. These data showed that the alterations in hepatic lipogenesis observed during TAM administration are related to changes in the activities of lipogenic enzymes and probably are a consequence of alterations in plasma insulin concentration. Disturbances in lipid metabolism should play an important role in the pathogenesis of liver damage and its physiological significance could involve metabolic changes in proliferative and neoplastic liver diseases.
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PMID:Lipogenesis and cholesterogenesis de novo in liver and adipose tissue. Alterations of lipid metabolism by the effect of short- and long-term thioacetamide administration to rats. 264 16

Insulin promotes an association between acetyl CoA carboxylase and acetyl CoA carboxylase phosphatase. The association between rat epididymal fat tissue carboxylase and the phosphatase occurs in both a tissue culture system and in vivo and is accompanied by an increase in acetyl CoA carboxylase activity.
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PMID:Effect of insulin on association of acetyl CoA carboxylase phosphatase and acetyl CoA carboxylase. 286 67

A high rate of lipogenesis in obese mice plays a major role in their excessive deposition of body lipid. Inhibition of lipogenesis may decrease their obesity. Therefore, we have investigated the effects of sodium 2-n-pentadecyl-benzimidazole-5-carboxylate (M & B 35347B), an inhibitor of acetyl-CoA carboxylase, on in-vivo lipogenesis in obese and lean mice. It significantly inhibited hepatic cholesterol and fatty acid synthesis, measured using 3H2O, in both lean and obese mice, with or without a glucose load. Brown adipose tissue (scapular) lipogenesis was decreased by M & B 35347B in obese mice but not in lean mice. In white adipose tissue, M & B 35347B did not affect the rates of lipogenesis in either scapular white, inguinal or epididymal depots of obese mice, or the inguinal and scapular white depot of lean mice. However, it doubled lipogenesis in the epididymal fat pad of lean mice. After a glucose load, lipogenesis in the lean epididymal fat pad was not inhibited but that in the inguinal depot was. M & B 35347B inhibited acetyl CoA carboxylase of adipose tissue in vitro but only a small inhibition was detected after in-vivo treatment. These different responses according to type of mouse, treatment and tissue site appear to stem from differences in inhibitor concentration and the importance of acetyl CoA carboxylase as the rate-limiting enzyme of lipogenesis. The weight gain of obese mice dosed orally (200 mg M & B 35347B/kg daily) for 60 days was unaffected and they continued to deposit excess body fat. This presumably occurred because of the lack of inhibition of fatty acid synthesis in white adipose tissue.
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PMID:Effect of sodium 2-n-pentadecyl-benzimidazole-5-carboxylate (M & B 35347B), an inhibitor of acetyl-CoA carboxylase, on lipogenesis and fat deposition in obese hyperglycaemic (ob/ob) and lean mice. 289 66


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