Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to understand the reasons for the increase in serum pseudocholinesterase activity in diabetes mellitus. Streptozotocin-induced diabetic rats were used for the study. Serum pseudocholinesterase activity increased with the induction of diabetes (381.5 units/l +/- 11.8) compared to the non-diabetic rats (243.1 units/l +/- 7.2). Serum triglycerides, total low density lipoprotein and glycerol also increased concurrently with the development of diabetes. Insulin treatment of the diabetic rats normalized serum glucose concomitant with the reduction of pseudocholinesterase activity, triglycerides, total low density lipoprotein and glycerol. Heparin injection appeared to activate lipoprotein lipase in the diabetic rats by showing a marked fall in serum triglyceride and total low density lipoprotein levels but not in pseudocholinesterase activity. Administration of tetraisopropylpyrophosphoramide a specific pseudocholinesterase inhibitor, inhibited serum and adipose tissue pseudocholinesterase activity by greater than 80% and liver greater than 50%. Concurrent with the inhibition of pseudocholinesterase activity serum triglyceride, low density lipoprotein and glycerol decreased significantly. In normal rats treatment with tetraisopropylpyrophosphoramide also reduced serum lipoproteins markedly, while glycerol only showed a marginal decrease. Glycerol was used as a marker of adipose tissue lipolysis and total low density lipoprotein which is defined as lipoproteins of density less than 1.063 (LDL + VLDL).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relationship between serum pseudocholinesterase and triglycerides in experimentally induced diabetes mellitus in rats. 186 86

Accuracy in measurement of plasma free fatty acids (FFA), and therefore prevention of the in vitro lipolysis, is a crucial step to understand the physiologic role of plasma FFA and their relationships in the pathogenesis of important metabolic disorders such as central obesity, insulin resistance, and diabetes mellitus. As lipoprotein triglyceride-fatty acids are elevated in these states, in vitro lipolysis of triglycerides may artifactually increase FFA. Plasma FFA were measured in subjects before and after heparin administration, under different experimental conditions affecting the in vitro activity of lipoprotein lipase (LPL) and hepatic lipase (HL). Paraoxon, a cholinesterase inhibitor neurotoxin known to block plasma lipolytic activity, and preextraction timing and temperature of collection were tested. Paraoxon was required to prevent triglyceride hydrolysis in: a) preheparin plasma allowed to stand at room temperature (21 degrees C) for 2 h, before being frozen at -20 degrees C (FFA = 1817 +/- 291 vs. 698 +/- 66 microEq/l, P < 0.005, mean +/- SEM, without and with paraoxon, respectively); and b) in postheparin plasma immediately stored at -20 degrees C (FFA = 2682 +/- 357 vs. 1299 +/- 150 microEq/l, P < 0.005, without and with paraoxon, respectively). No difference in the FFA level was found in preheparin plasma collected either with or without paraoxon when: a) the samples were placed in ice and immediately assayed; b) the specimens were immediately frozen at -70 degrees C and assayed 60 days later.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Analysis of techniques to obtain plasma for measurement of levels of free fatty acids. 835 49

The relation of plasma lipids and pseudocholinesterase (PChE) activity was studied in rats made hypothyroid by treatment with propylthiouracil (0.05% in drinking water for 28 days) and in hypothyroid patients prior and after L-thyroxine-therapy (1. week 25-50 microg, 2.-4. week 100 microg daily). In rats, thyroid hormone deficiency caused a significant increase in plasma and adipose tissue PChE activity as well as total plasma cholesterol (TC) concentration, and a decrease in plasma triglyceride (TG) concentration. In contrast to rats, thyroid-deficient humans demonstrated a decrease in plasma PChE activity and an increase in both TC and TG, in comparison with euthyroid controls. After one month's therapy with L-thyroxine, reversion of PChE activity and lipid concentrations occurred. The opposite changes of PChE elicited by thyroid hormone deficiency in men and rats are similar to the respective changes in lipoprotein lipase (LPL) activity, observed by other authors. The inverse correlation between both PChE and LPL activity and TG concentration suggests that PChE, similarly to LPL, may be involved in TG hydrolysis.
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PMID:The relation between plasma lipid levels and pseudocholinesterase activity in hypothyroidism. 956 55

An end user computing system (EUC) is usually part of the laboratory information system. Effective use of this EUC system is described in this article. The first application of this system is for monitoring the turn-around time (TAT) of laboratory work flow. Precise time sequential data were analyzed using this end user computing system. Weekly fluctuations of TAT depended on the cyclic changes in requisition numbers of test samples. Another application of EUC was phenotype screening of genetic abnormalities. Screenings from high triglyceride and low HDL cholesterol were effective for the phenotype screening for genetic lipoprotein lipase abnormalities, and phenotype screening from high albumin cholinesterase ratio was effective for genetic abnormalities causing silent cholinesterase. Investigational application of EUC was demonstrated in two areas of laboratory research.
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PMID:[Investigative application of a laboratory database]. 1121 71

The central role of the intracellular enzyme hormone-sensitive lipase (HSL) in regulating fatty acid metabolism makes it an interesting pharmacological target for the treatment of insulin resistant and dyslipidemic disorders where a decrease in delivery of fatty acids to the circulation is desirable, e.g., in individuals with type 2 diabetes, metabolic syndrome, or impaired glucose tolerance. On the basis of a lead structure from high throughput screening, we have identified a very potent type of carbamoyl-triazole inhibitors of HSL. As part of the lead optimization program, four new classes of carbamoyl-triazoles were synthesized and tested with respect to potency, efficacy and selectivity. Methyl-phenyl-carbamoyl-triazoles were identified as potent and efficacious HSL inhibitors. These compounds do not inhibit other hydrolases such as hepatic lipase, lipoprotein lipase, pancreatic lipase, and butyrylcholine esterase. However, the inhibitors 4b and 4g with IC(50) values for HSL of 0.17 and 0.25 microM, respectively, were the only inhibitors selective against acetylcholine esterase. A reversible pseudosubstrate inhibition mechanism is proposed for this class of inhibitors.
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PMID:Synthesis and structure-activity relationship for a novel class of potent and selective carbamoyl-triazole based inhibitors of hormone sensitive lipase. 1471 11

Lipases sensitive to organophosphorus (OP) inhibitors play critical roles in cell regulation, nutrition, and disease, but little is known on the toxicological aspects in mammals. To help fill this gap, six lipases or lipase-like proteins are assayed for OP sensitivity in vitro under standard conditions (25 degrees C, 15 min incubation). Postheparin serum lipase, lipoprotein lipase (LPL) (two sources), pancreatic lipase, monoacylglycerol (MAG) lipase, cholesterol esterase, and KIAA1363 are considered with 32 OP pesticides and related compounds. Postheparin lipolytic activity in rat serum is inhibited by 14 OPs, including chlorpyrifos oxon (IC50 50-97 nM). LPL (bovine milk and Pseudomonas) generally is less inhibited by the insecticides or activated oxons, but the milk enzyme is very sensitive to six fluorophosphonates and benzodioxaphosphorin oxides (IC50 7-20 nM). Porcine pancreatic lipase is very sensitive to dioctyl 4-nitrophenyl phosphate (IC50 8 nM), MAG lipase of mouse brain to O-4-nitrophenyl methyldodecylphosphinate (IC50 0.6 nM), and cholesterol esterase (bovine pancreas) to all of the classes of OPs tested (IC50 < 10 nM for 17 compounds). KIAA1363 is sensitive to numerous OPs, including two O-4-nitrophenyl compounds (IC50 3-4 nM). In an overview, inhibition of 28 serine hydrolases (including lipases) by eight OPs (chlorpyrifos oxon, diazoxon, paraoxon, dichlorvos, and four nonpesticides) showed that brain acetylcholinesterase is usually less sensitive than butyrylcholinesterase, liver esterase, cholesterol esterase, and KIAA1363. In general, each lipase (like each serine hydrolase) has a different spectrum of OP sensitivity, and individual OPs have unique ranking of potency for inhibition of serine hydrolases.
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PMID:Each lipase has a unique sensitivity profile for organophosphorus inhibitors. 1644 51

The messenger RNA (mRNA) distribution of 60 proteins was examined in the 3 fractions obtained by collagenase digestion (fat cells and the nonfat cells comprising the tissue remaining after collagenase digestion [matrix] and the stromovascular cells) of omental adipose tissue obtained from morbidly obese women undergoing bariatric surgery. Fat cells were enriched by at least 3-fold as compared with nonfat cells in the mRNAs for retinol binding protein 4, angiotensinogen, adipsin, glutathione peroxidase 3, uncoupling protein 2, peroxisome proliferator-activated receptor gamma, cell death-inducing DFFA-like effector A, fat-specific protein 27, 11beta-hydroxysteroid dehydrogenase 1, glycerol channel aquaporin 7, NADPH:quinone oxidoreductase 1, cyclic adenosine monophosphate phosphodiesterase 3B, glyceraldehyde-3-phosphate dehydrogenase, insulin receptor, and amyloid A1. Fat cells were also enriched by at least 26-fold in the mRNAs for proteins involved in lipolysis such as hormone-sensitive lipase, lipoprotein lipase, adipose tissue triglyceride lipase, and FAT/CD36. The relative distribution of mRNAs in cultured preadipocytes was also compared with that of in vitro differentiated adipocytes derived from human omental adipose tissue. Cultured preadipocytes had far lower levels of the mRNAs for inflammatory proteins than the nonfat cells of omental adipose tissue. The nonfat cells were enriched by at least 5-fold in the mRNAs for proteins involved in the inflammatory response such as tumor necrosis factor alpha, interleukin lbeta, cyclooxygenase 2, interleukin 24, interleukin 6, and monocyte chemoattractant protein 1 plus the mRNAs for osteopontin, vaspin, endothelin, angiotensin II receptor 1, butyrylcholinesterase, lipocalin 2, and plasminogen activator inhibitor 1. The cells in the adipose tissue matrix were enriched at least 3-fold as compared with the isolated stromovascular cells in the mRNAs for proteins related to the inflammatory response, as well as osteopontin and endothelial nitric oxide synthase. We conclude that the mRNAs for inflammatory proteins are primarily present in the nonfat cells of human omental adipose tissue.
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PMID:Comparison of messenger RNA distribution for 60 proteins in fat cells vs the nonfat cells of human omental adipose tissue. 1855 44

Carboxylesterases (Carboxyl ester hydrolase) include two groups of enzymes, namely non-specific esterases (EC 3.1.1.1) and lipases (EC 3.1.1.3) which have been early differentiated on the basis of their substrate specificity. Esterases hydrolyse solutions of water-soluble short acyl chain esters and are inactive against water-insoluble long chain triacylglycerols which, in turn, are specifically hydrolyzed by lipases. Based on the comparison of the primary structures, three families of sequence-related carboxylesterases, namely the lipoprotein lipase family (L-family), the hormonesensitive lipase family (H-family) and the cholinesterase family (C-family) have been identified. Using solutions and emulsions of vinyl, glyceryl and p-nitrophenyl esters, we have reinvestigated the kinetic properties of some esterases and lipases of the H- and C-families. Results indicate that esterases and lipases, which are both active on soluble esters, can be differentiated by their value of Km. Moreover, esterase, unlike lipases, are inactive against water-insoluble esters as vinyl laurate and trioctanoylglycerol. From the the comparison of structural features of sequence-related esterases and lipases, it appears that lipases, unlike esterases, display a significant difference in the distribution of hydrophobic amino acid residues at vicinity of their active site. This observation supports the hypothesis of the existence in lipases of a particular surface domain that specifically interacts with lipid-water interfaces and contributes to the transfer a single substrate molecule from the organized lipid-water interface (supersubstrate) to the catalytic site of the enzyme.
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PMID:Distinction between esterases and lipases: comparative biochemical properties of sequence-related carboxylesterases. 1950 78

This study was designed to investigate the effects of conjugated linoleic acid (CLA) supplementation and endurance exercise training-induced changes on post-heparin lipoprotein lipase (PH-LPL) and butyrylcholinesterase (BChE) activities along with leptin, insulin and lipid levels in plasma by a randomized double blind experiment. Eighteen sedentary male volunteers were randomly divided into CLA and Placebo (PLC) supplementation groups. Both groups underwent daily supplementation of either 3g CLA or 3g placebo for 30 days, respectively, and performed exercise on a bicycle ergometer 3 times per week for 30-40 min at 50% VO2 peak workload. For plasma glucose, insulin and leptin levels and BChE activity fasting blood was used. For PH-LPL measurements, blood was collected 15 min after 50 IU/kg iv heparin injection. In all groups, there is a statistically significant decrease in BChE (p = 0.03, p = 0.02) and leptin (p = 0.002), insulin and HOMA-IR levels (p = 0.02). Exercise with or without CLA supplementation decreased insulin levels and increased insulin sensitivity. PH-LPL activity was increased significantly in both groups, displaying increased fatty acid mobilization. We conclude that though CLA supplementation and exercise can affect these parameters, CLA is not more effective than exercise alone. Hence, a prolonged supplementation regime may be more effective. Taken together in our small study group, our findings display that BChE is a potential marker for synthetic function of liver, fat metabolism, an obesity marker, a function long overlooked.
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PMID:Effects of conjugated linoleic acid supplementation and exercise on post-heparin lipoprotein lipase, butyrylcholinesterase, blood lipid profile and glucose metabolism in young men. 2307 71