Pseudocholinesterase Research Articles

Determination of Pseudocholinesterase Activity in the Gingival Crevicular Fluid, Saliva, and Serum from Patients with Juvenile Periodontitis and Rapidly Progressive Periodontitis

By use of a spectrophotometric method, pseudocholinesterase (PCE) activities were determined in gingival crevicular fluid (GCF), saliva, and serum from patients with juvenile periodontitis (JP) and rapidly progressive periodontitis (RPP) and from controls. The PCE activity in the GCF samples was 181 +/- 48 U/L in the JP group, 588 +/- 135 U/L in the RPP group, and 88.5 +/- 29.1 U/L in the control group. Saliva PCE activity levels were 9.1 +/- 1.7 U/L in the JP group, 21.8 +/- 4.5 U/L in the RPP group, and 12.7 +/- 0.8 U/L in the control group. GCF contained a higher PCE activity than saliva but a lower one than that of serum. The RPP group had a significantly higher PCE activity in both the GCF and saliva samples. No significant differences could be found regarding serum enzyme levels. Also, no significant correlations were present between biochemical values and the severity of periodontal disease. GCF may be an important source for the PCE content of saliva. It is suggested that the increased PCE activity seen in RPP patients might be caused by either the direct production of esterases by bacteria or the induction of esterases during periodontal destruction.

Pseudocholinesterase Activity in Human Cerebrospinal Fluid

In view of conflicting data concerning metabolism of ester type local anesthetics in CSF, the authors collected a sample of CSF from a series of 10 patients scheduled for spinal anesthesia. In addition, 4 patients with a history of recent bleeding into the CSF who were under general anesthesia had a CSF sample collected as well as 3 ml of venous blood. In all samples, pseudocholinesterase (PCHE) activity and dibucaine numbers (DN) were determined.

Inhibitory pattern of tissue esterases in rats fed dietary pirimiphos-methyl.

Activities of Acetylcholinesterase (AChE) in brain and erythrocytes, pseudocholinesterase (PChE) in plasma and non-specific carboxylesterase (NSE) in brain, liver, plasma and kidney were assayed at weekly intervals in growing male rats fed dietary pirimiphos-methyl at dosages of 1000, and 1500 ppm for a period of 28 days. Significant inhibition of tissue esterases were observed at the end of 7 days at both the dosages and the enzyme activities remained markedly inhibited at subsequent intervals. Activities of all enzymes (excepting Brain AChE) returned to normal levels following a 7-day maintenance on the insecticide-free diet implicating that pirimiphos-methyl induced little or no permanent tissue damage. The results suggest that plasma NSE level may also serve as a sensitive indicator in monitoring OPI exposure.

A comprehensive study of the stability of cocaine and its metabolites.

The stability of cocaine (COC) in blood bank blood, postmortem human whole blood, and buffers was evaluated with consideration for the presence of the degradation products, benzoylecgonine (BE) and ecgonine methyl ester (EME). At COC concentrations commonly seen, the rate of COC hydrolysis was independent of concentration. COC was stable in blood for at least 150 days if the blood was adjusted to pH 5 and preserved with 2% NaF or organophosphates and maintained at 4 degrees C or lower. Without preservation, most COC hydrolyzed to EME. The addition of a pseudocholinesterase (PChE) inhibitor without a reduction of pH caused COC to hydrolyze to BE. COC also hydrolyzed to BE in phosphate buffer. The rate of COC hydrolysis in all studies increased with increasing pH and temperature. COC was more stable in unpreserved postmortem blood than blood bank blood due to the lower pH of the former. The incubation of COC in enzyme solutions provided further evidence of the generally accepted hypothesis that COC is hydrolyzed to EME by PChE and to BE by chemical hydrolysis. In unpreserved blood, BE was more stable than EME at room temperature. There was little loss of BE or EME at refrigerated temperature over a period of 35 days and no evidence that EME or BE could be hydrolyzed enzymatically.

Pseudocholinesterase Activity in Human Cerebrospinal Fluid

Pseudocholinesterase (PCHE) activity and dibucaine numbers (DN) in the cerebrospinal fluid (CSF) and plasma of 10 ASA physical status 1 and 2 patients were measured using a kinetic method. CSF had a mean PCHE activity of 0.018 +/- 0.013 unit/ml with a DN of 59 +/- 4. Whereas, PCHE activity and DN in the plasma were 0.960 +/- 0.12 units/ml and 84 +/- 3, respectively. We also measured PCHE activity and DN in the CSF and plasma of 4 patients in whom there was a recent history of intraventricular bleeding. These patients had a CSF PCHE activity of 0.340 +/- 0.07 units/ml (DN = 78 +/- 3) and a plasma PCHE activity of 0.950 +/- 0.10 units/ml (DN = 82 +/- 2). Our data show that there is a low activity of PCHE in CSF, 1/20-1/100th that of plasma. Our data also show that PCHE activity increased to 1/4 to 1/2 that of plasma in CSF of patients with bleeding into CSF.

Relationship between pseudochol inesterase and some whole blood parameters

A study of the possible relationship between ChE activity and number of red blood cells and white cells, haemoglobin content, haematocrit value, colour index (C.I.), mean corpuscular haemoglobin (M.C.V.), mean corpuscular haemoglobin (M.C.H.), mean corpuscular haemoglobin concentration (M.C.H.C.) has been carried out. A significant linear relationship (p<0.05) with red blood cells, haemoglobin content and haematocrit value is obtained for men and with haemoglobin content and M.C.H.C. for women. No relationship is observed for the other parameters studied.

Serum pseudocholinesterase levels in murine C3H mammary adenocarcinoma.

Serum pseudocholinesterase (PSC) levels may be depressed in persons with malignancy. Deficiency of this enzyme can lead to prolonged apnea in patients who receive succinylcholine. An animal model was developed to study this phenomenon in a controlled setting. C3H/HeJ mice inoculated subcutaneously with C3H mammary adenocarcinoma demonstrated lowering of their PSC levels. This decrease was attenuated by chemotherapy with intraperitoneal cyclophosphamide which also prolonged survival. Non-tumor bearing control animals identically treated with cyclophosphamide experienced a transient drop in PSC on the 29th day which reverted to control values by the 36th day. No gradient of PSC could be demonstrated across a tumor's vascular bed. The effect of other chemotherapy agents on PSC is unknown. A possible role for PSC as a non-specific marker for malignancy is worthy of further study.

Relationship between pseudocholinesterase and lipids in hyperlipoproteinaemia

The biological r d e of serum pseudocholinesterase (PChE) is enigmatic: the protein is normally detected and defined in terms of its catalytic hydrolysis of choline esters but no necessity for such enzymic activity in serum has ever been demonstrated. However, the now well-established association between obesity and PChE in genetic and dietary animal models (Kutty et a[., 1981, 1983), and also in clinical situations (Cucuianu et al., 1968; Chu et al., 1978), suggests that PChE may play a significant part in the aetiology of coronary heart disease (CHD), a common end-stage consequence of obesity and hyperlipoproteinaemia. Serum was collected after an overnight fast from 66 patients with confirmed C H D (80% males; age 35-60 years) and 83 matched controls. Sixteen of the C H D patients were re-investigated after treatment for 2-3 months with diet, or medication, or both, to reduce serum lipids. Cholesterol and triglycerides were measured by standard methods. Lowdensity lipoprotein (LDL) was measured by a turbidimetric method (Walton & Scott, 1964) that included both LDL and very-low-density lipoprotein (VLDL). PChE was measured with butyrylthiocholine iodide substrate (Dietz et al., 1973). Serum PChE activities in the control (mean = 3.15 pmol of thiocholine/min per ml of serum; S.D. = 0.40) did not differ significantly with age or sex in adult subjects. However, 34 C H D patients (50%) had PChE activities exceeding the control 95th percentile, and all C H D patients’ PChE activities exceeded the control mean (Fig. 1). As expected, 50% of the patients were hypercholesterolaemic and 80% were hypertriglyceridaemic by accepted clinical criteria. Correlation analysis of the combined observations from patients and controls demonstrated that PChE is positively correlated with LDL (r = 0.51) and its associated lipids, cholesterol ( r = 0.48) and triglycerides (r = 0.52). Of even greater potential significance is that 18% of the C H D patients with significantly elevated PChE had normal lipid levels. During treatment, the patients’ PChE activities dropped from 4.7 f 0.34 to 3.9 k 0.26pmol of thiocholinelmin per ml ( I = 10.1) in concert with declines in cholesterol, triglyceride and total LDL levels. Animal models (Kutty et al., 1981, 1983) suggest that excess dietary intake is a major determinant of the PChE levels. Genetically obese (oblob), diabetic (dbldb) and normal mice with gold thioglucose-induced obesity exhibit a marked increase (50-150%) in liver and serum PChE activity when diet is unrestricted. Levels of PChE are almost normal when these hyperphagic animals are maintained on restricted diets. The parallel between these experimental models and hypertrophic obesity in humans is clear. However, the problem remains of non-obese, normolipidaemic C H D patients with significantly elevated serum PChE: what is the aetiology of hyperpseudocholinesterasaemia in these individuals and is non-dietary elevated serum PChE an independent risk factor in susceptibility to atheroscleortic heart disease? How could elevated PChE levels be implicated in atherosclerosis? It is possible that the true function of PChE

Acute biological effects of commercial cresyl diphenyl phosphate in rats

A commercial cresyl diphenyl phosphate preparation was analyzed to contain approximately 35% of triphenyl phosphate, 45% of cresyl diphenyl phosphates, 18% of dicresyl phenyl phosphates and 2% of tricresyl phosphates. The product was almost free of the o-cresyl isomers as revealed by the analysis of its alkaline hydrolysis products. A single intraperitoneal injection (150 or 3 mg/kg) caused an induction of microsomal cytochrome P-450 in the liver of Wistar rats with a concomitant increase in the activities of mixed function monooxygenases and proliferation of smooth endoplasmic reticulum 24 h after the treatment. These effects were not detected in the kidneys. The morphological changes in hepatocytes included the enlargement of nuclei and mitochondria with increased cristae. The hepatic morphology returned to normal 2 weeks after the treatment. The activity of pseudocholine esterase in blood was inhibited 4 h and 24 h after the injection but the effect levelled off. The concentration of the organophosphates in blood and liver decreased rapidly with only traces detected in blood after 24 h. No effects on the activities of cerebral and muscle acetylcholine esterase were observed. The treatment (300 mg/kg) inhibited the brain — 2′,3′-cyclic nucleotide 3′-phosphohydrolase through the 2-week observation period associated with demyelination in peripheral nerves.

A peptidase activity exhibited by human serum pseudocholinesterase.

The identity of a peptidase activity with human serum pseudocholinesterase (PsChE) purified to apparent homogeneity was demonstrated by co-elution of both peptidase and PsChE activities from procainamide-Sepharose and concanavalin-A--Sepharose affinity chromatographic columns; comigration on polyacrylamide gel electrophoresis; co-elution on Sephadex G-200 gel filtration and coprecipitation at different dilutions of an antibody raised against purified PsChE. The purified enzyme showed a single protein band on gel electrophoresis under non-denaturing conditions. SDS gel electrophoresis under reducing conditions, followed by silver staining, also gave a single protein band (Mr approximately equal to 90,000). Peptidase activity using different peptides showed the release of C-terminal amino acids. Blocking the carboxy terminal by an amide or ester group did not prevent the hydrolysis of peptides. There was no evidence for release of N-terminal amino acids. Potent anionic or esterase site inhibitors of PsChE, such as eserine sulphate, neostigmine, procainamide, ethopropazine, imipramine, diisopropylfluorophosphate, tetra-isopropylpyrophosphoramide and phenyl boronic acid, did not inhibit the peptidase activity. An anionic site inhibitor (neostigmine or eserine) in combination with an esterase site inhibitor (diisopropylfluorophosphate) also did not inhibit the peptidase. However, the choline esters (acetylcholine, butyrylcholine, propionylcholine, benzoylcholine and succinylcholine) markedly inhibited the peptidase activity in parallel to PsChE. Choline alone or in combination with acetate, butyrate, propionate, benzoate or succinate did not significantly inhibit the peptidase activity. It appeared that inhibitor compounds which bind to both the anionic and esteratic sites simultaneously (like the substrate analogues choline esters) could inhibit the peptidase activity possibly through conformational changes affecting a peptidase domain.

Sequential changes of the autonomic nervous system in the development of cysteamine-induced duodenal ulcer, histochemical and quantitative studies.

We studied how the autonomic nervous system participated in the develop-ment of experimental duodenal ulcers due to cysteamine hydrochloride. Sym-pathetic fibers showed a slight increase in activities in the duodenal mucosa 1 h after cysteamine administration, and a marked decrease thereafter. The release of noradrenaline (NA) into the blood was suggested. Of the activities of para-sympathetic fibers, true cholinesterase activities, that are concerned with secre-tions, began to increase 1 h after cysteamine administration, which was observed most notably around the Brunner's glands in the duodenal submucosa, peaked at 8h, and then decreased or disappeared at 24h when ulcer formation was established. Pseudo cholinesterase activities that are concerned with motor func-tion, decreased over time with a resulting decrease in gastroduodenal move-ments and emptying. Meanwhile, it was confirmed by estimation of NA and cholinesterase (ChE) by means of a fluorescent histochemical study. The above findings suggest that, though the sympathetic and parasympathetic systems play their roles with a complicated interrelationship in the development of cysteamine-induced duodenal ulcers, sympathetic fibers are initially depressed, and ulcera-tion develops and advances under the parasympathetic dominance. In other words, the development of ulcers seems to depend more on the parasympathetic system than on the sympathetic system.

Determination of cholinesterase and acetylcholinesterase in amniotic fluid

The determination of acetylcholinesterase (AChE) has been shown to be as specific as alphafetoprotein (AFP) for the prenatal detection of open neural tube defects although AFP remains the method of choice. This paper describes a semi-automated technique for the analysis of acetylcholinesterase in amniotic fluid that: A) reduces the cost of the procedure; B) allows for a larger number of samples to be run at a time; and C) provides for more accurate and reproducible procedures and results. Six fetuses with neural tube defects (2 with gastroschisis and 3 where one twin was dead) were detected and found to have elevated AChE, TChE and 2 bands by electrophoresis. Quality control procedures using both pure enzyme and amniotic fluid with low and high levels of the enzyme are described. The analysis of 340 amniotic fluids of normal pregnancies indicates that the normal value for AChE is 5.17 +/- 2.63 mU/ml (97% confidence interval for the mean 4.84-5.49 mU/ml. A group of 27 abnormal pregnancies provides evidence that fetal vomiting and regurgitation, fetal demise, multiple cysts syndrome, idiopathic IUGR, arthrogryposis multiplex, hydrocephaly (stenosis of aqueductus), trisomy 21, trisomy 18, hydronephrosis, pyloric stenosis, heart malformation, ectopia cordis and multiple gestation produce elevated levels of pseudocholinesterase (PChE) in amniotic fluid. The use of pseudocholinesterase levels in amniotic fluid for prenatal diagnosis is proposed and discussed in view of its elevated levels in abnormal pregnancies where AChE is normal. The normal values for PChE are 23.86 mU/ml (mean) and 5.83 for standard deviation. Electrophoretic analysis was performed on all samples with values higher than one standard deviation above the mean.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of ethopropazine and BW 284C51 as selective inhibitors for cholinesterases from various species

1. Both inhibitors tested were still able to depress the cholinesterase (ChE) for which it is not selective (BW 284C51 for pseudo ChE, ethopropazine for the true ChE) provided the concentration was high (>10 −2M). 2. BW 284C51 totally depressed the true ChE activity from bovine erythrocytes at a concentration of 10 −6M. This inhibitor concentration gave no depression of pseudo ChE activity from horse serum. 3. Ethopropazine totally depressed the pseudo ChE activity from horse serum at a concentration of 5 × 10 −5M. The true ChE was not inhibited at this concentration. 4. For true ChE from bovine erythrocytes and pseudo ChE from horse serum BW 284C51 and ethopropazine therefore certainly have a potential as selective ChE inhibitors. 5. Ethopropazine at a concentration of 5 × 10 −6 M completely inhibited the pseudo ChE activity in rat plasma and cortex without affecting true ChE activity. 6. BW 284C51 at a concentration of 10 −6 M gave a total depression of the true ChE activity in these preparations. 7. In rat plasma, however, a considerable part of the pseudo ChE activity was depressed at this concentration.

Ascites to serum ratio of pseudochol inesterase (PCHE): An approach to the differential diagnosis of ascites

Ascites to serum ratio of pseudochol inesterase (PCHE): An approach to the differential diagnosis of ascites

Quantitative estimation of the density ratios of cholinesterase bands in human amniotic fluids

Quantitative densitometry has been used to measure cholinesterase bands in amniotic fluids after polyacrylamide gel electrophoresis. The ratio of acetylcholinesterase (AChE) to pseudocholinesterase (PChE) could be used both for diagnosis and for differential diagnosis of fetal abnormalities. Normal amniotic fluids had AChE/PChE density ratios of zero, while neural tube defect fluids were all above 0.15. Ventral wall defect samples had ratios below 0.15, as did false positives due to contamination with human fetal serum. In samples which had been accidentally contaminated with fetal calf serum, density ratios were above 0.15. Similar results were obtained with both slab gel and rod gel electrophoresis.

Spontaneous reactivation of mouse plasma cholinesterase after inhibition by various organophosphorus compounds.

We investigated the spontaneous reactivation of mouse plasma cholinesterase (ChE) after inhibition by various organophosphorus compounds. The remarkable spontaneous reactivations during storage at 24 degrees C were observed in plasma ChE prepared 30 min after oral administration of three O,O-dimethyl organophosphorus compounds, i.e. malathion, methylparathion and cyanox; while the spontaneous reactivation did not occur after inhibition by tolclofos-methyl, one of O,O-dimethyl organophosphorus compounds. The plasma ChEs inhibited by surecide, salithion and leptophos, which contain no O,O-dimethyl moiety, were not reactivated or only slightly so. These results suggest that a more sufficient attention should be paid in the determination of activity of plasma ChE inhibited by O,O-dimethyl organophosphorus compounds than that of plasma ChE inhibited by organophosphorus compounds without O,O-dimethyl moiety, since plasma ChE inhibited by the organophosphorus compounds with O,O-dimethyl moiety, except for tolclofos-methyl, was more easily reactivated, and the correct activity of inhibited plasma ChE can not be obtained without attention to the spontaneous reactivation. Furthermore, these spontaneous reactivations were examined by using butyrylthiocholine as well as acetylthiocholine as a substrate, and results showed that there was little difference between the spontaneous reactivations observed in using acetylthiocholine and butyrylthiocholine. So, it is concluded that these spontaneous reactivations take place only in pseudo ChE.

Pseudocholinesterase Activity and Its Origin in Human Oral Fluid

Pseudocholinesterase (PCE) activity in oral fluid of 31 male and 24 female subjects was determined using butyrylthiocholine iodide as substrate. Males had approximately twice as much salivary PCE activity as did females [4.8 +/- 2.4 (S.D.) U/1 and 2.2 +/- 1.5 (S.D.) U/1, respectively]. The activity was not much affected by salivary flow rate, although in men it was a little higher in stimulated than in unstimulated saliva. Salivary PCE activity showed diurnal variation. Accordingly, activities were about three times greater at four a.m. than at four p.m. Parotid PCE activity correlated with that of whole saliva in both men and women. PCE activity in crevicular fluid (four subjects) was 120 +/- 48 (S.D.) U/1. An elevation of PCE activity in oral fluid was found after experimental induction of gingival inflammation. However, the mean PCE activity of patients with clinical gingivitis was not significantly higher than that of healthy subjects, although some exceptionally high values were found. Sonicated samples of plaque did not contain any PCE activity. No correlation existed between PCE activities in saliva and serum.

The relationships between human serum pseudocholinesterase, lipoproteins, and apolipoproteins (APOHDL)

During recent years there has been an increasing number of studies concerning metabolizing enzymes during lipoprotein catabolism. It is well documented that lecithin-cholesterol acyltransferase (LCAT, ED 2.3.1.43) and lipoprotein lipase (EC 3.1.1.34) take part with these reactions (1). In addition to these enzymes there has been evidence that pseudocholinesterase (EC 3.1.1.8.) is also associated with lipid metabolism (2). A relationship between serum pseudocholinesterase and low density lipoprotein (LDL) has been shown on the basis of ultrasonication studies (3) and after artifical induction of hyperlipidemia in vitro and in vivo (4). Because pseudocholinesterase activity has been previously measured only in whole serum and in DLD, our purpose has been to find out if there is any activity in other lipoprotein fractions. In addition to whole enzyme activity we investigated the distribution of pseudocholinesterase (PCE) isoenzymes in different fractions. As previously reported, LCAT and lipoprotein lipase need as cofactor, a specific apolipoprotein (5). We also studied a possible connection between HDL (high density lipoprotein) apolipoproteins (apoA-I, A-II, E, and total apoC) and PCE activity.

True and pseudo cholinesterases in depression.

True and pseudo cholinesterases in depression.

Pseudocholinesterase--a clinical assessment.

Serum pseudocholinesterase (PC) levels were analyzed retrospectively against serum albumin, total lymphocyte count, and hematocrit using 4 to 15 data sets in 17 seriously ill surgical patients who received total parenteral alimentation for 4--21 days. A statistically significant correlation was found between PC and serum albumin but not between PC and total lymphocyte count or hematocrit. Low PC levels are found with acquired nutritional deprivation and in certain abnormal genetic states. When the use of succinylcholine is contemplated, PC levels should be measured in patients who have a low serum albumin or have an acquired nutritional deficiency.