Pseudocholinesterase Activity Research Articles

Etude critique d'une methode de dosage automatisee des pseudocholinesterases selon la reaction d'hestrin

1. Attempts were made to develop an automated method which could perform quantitative measurements of total serum pseudocholinesterase (E.C. 3.1.1.8.) activity and dibucaïne number by use of the Hestrin reaction. 2. Unusual patterns of inhibition were observed with dibucaïne; some inhibited sera gave absorbance values which were higher than the absorbance of the substrate itself. This is due to the fact that certain sera contain “ester-like” substances which dialyze and thereafter react with hydroxylamine to produce a complex absorbing at the same wavelength as the acylhydroxamate ferric complex. 3. Application of the Hestrin reaction for the determination of total serum pseudocholinesterase activity and dibucaïne number with an automated system equipped with a dialyzer therefore requires corrections for serum blank values. Consequently, the procedure does not appear to be practical for large scale determinations of these parameters.

Etude critique d'une methode de dosage automatisee des pseudocholinesterases selon la reaction d'hestrin*

Attempts were made to develop an automated method which could perform quantitative measurements of total serum pseudocholinesterase (E.C. 3.1.1.8.) activity and dibucaïne number by use of the Hestrin reaction. Unusual patterns of inhibition were observed with dibucaïne; some inhibited sera gave absorbance values which were higher than the absorbance of the substrate itself. This is due to the fact that certain sera contain “ester-like” substances which dialyze and thereafter react with hydroxylamine to produce a complex absorbing at the same wavelength as the acylhydroxamate ferric complex. Application of the Hestrin reaction for the determination of total serum pseudocholinesterase activity and dibucaïne number with an automated system equipped with a dialyzer therefore requires corrections for serum blank values. Consequently, the procedure does not appear to be practical for large scale determinations of these parameters.

An electron-microscopic study of cholinesterase distribution in the rat adrenal medulla.

SUMMARYThe distribution of cholinesterase activity in the rat adrenal medulla was studied after initial fixation with glutaraldehyde, which preserves the osmiophilia of the noradrenaline‐containing cells. Staining for true cholinesterase activity was associated with all the identifiable elements of the preganglionic sympathetic innervation. The morphology and enzyme staining of the endings on the chromaffin cells was similar to that seen in cholinergic synapses in the central nervous system. The endings contained occasional dense‐cored vesicles and the possible significance of such vesicles at an undoubted cholinergic synapse is discussed. Staining for pseudocholinesterase activity, by contrast, was associated particularly with the Schwann cells and to a lesser extent with the chromaffin cells, but not with the axons and their processes.

Cholinesterases of rat sympathetic ganglia after immunosympathectomy, decentralization and axotomy.

Abstract— Immunosympathectomy was produced in Sprague‐Dawley rats by the subcutaneous injection of 300 units of nerve growth factor (NGF)‐antiserum (1.56 mg of freeze‐dried serum)/g/day for 6 days, the first dose being given 5–8 hr after birth. The immunosympathectomized rats and their control littermates were killed 2½ and 7 months after birth.Ganglionic acetylcholinesterase and pseudocholinesterase activities were measured by an adaption (Kungman, Kungman and Pouszczuk, 1968) of the colorimetric method of Ellman, Courtney, Andres and Featherstone (1961). Following immunosympathectomy the activities of these enzymes decreased significantly in superior cervical, stellate, thoracic chain, cardiac (abdominal), coeliac and superior mesenteric ganglia. The reduction of the acetylcholinesterase activity was greater than expected in a number of sympathetic ganglia, e.g. superior cervical, stellate, coeliac and cardiac ganglia, if one considered that only the postganglionic neurons were affected by immunosympathectomy. The activities of these enzymes were also reduced in the cervical sympathetic trunks from NGF‐antiserum‐treated rats. By means of decentralization and axotomy it was shown that 45 per cent of the total ganglionic acetylcholinesterase activity was associated with the preganglionic and 55 per cent with the postganglionic elements of the superior cervical ganglion from control rats. It was concluded that immunosympathectomy also affects the preganglionic sympathetic neurons. It is not known whether this is a primary effect of the NGF‐antiserum or a secondary effect resulting from the absence of over 90 per cent of the postganglionic sympathetic cell bodies.

Acetyl- and pseudocholinesterase activities in sympathetic ganglia of rats.

Abstract—The quantitative method of Ellman, Courtney, Andres and Featherstone (1961) was adapted to a differential assay for the determination of acetyl‐ and pseudocholinesterase activities of sympathetic ganglia of rats. The activities of the cholinesterases of superior cervical, stellate and thoracic chain ganglia and of the abdominal ganglionic complexes in apposition to the superior mesenteric and coeliac arteries (superior mesenteric, coeliac and cardiac ganglia) were measured. B.W.284C51 dibromide, 5 × 10−5m, and ethopropazine hydrochloride, 3·15 × 10−5m, were employed to inhibit selectively acetyl‐ and pseudocholinesterases, respectively. Linearity was shown to be maintained with enzyme concentrations corresponding to 0·12‐0·5 mg of ganglion (wet wt.)/incubation. Under the experimental conditions of this assay, the rates of the reaction of ganglionic acetyl‐ and pseudocholinesterases were linear for time periods greater than those employed for calculating the rates of hydrolysis in the homogenates of sympathetic ganglia. Several experimental approaches were used to ascertain the specificity of the inhibitors and of the reaction.Of the total cholinesterase activity of sympathetic ganglia of rats, 55‐63 per cent was due to acetylcholinesterase and 31‐39 per cent to pseudocholinesterase. On the basis of the specific enzyme activity, superior cervical, stellate and superior mesenteric ganglia contained higher acetyl‐ and pseudocholinesterase activities than did thoracic chain, coeliac and cardiac (abdominal) ganglia. The specific activity of acetylcholinesterase was similar in rat and cat superior cervical ganglia and sympathetic cervical trunks while the pseudocholinesterase activity of these two tissues was somewhat lower in cats than in rats.

Pseudocholinesterase in obese and hyperlipemic subjects

It was found that serum pseudocholinesterase increases not only in obese sub- jects but also in hyperlipemic patients with normal body weight. A good statistical correlation was found between serum pseudocholinesterase on one hand, and both serum cholesterol and the logarithm of serum triglycérides concentration, on the other. It cannot be stated whether increased pseudocholinesterase activity should be correlated with a possible role of the enzyme in the metabolism of lipids or with an unspecific and rather general stimulation of protein synthesis in the liver of obese and hyperlipemic subjects.

Cholinesterases in the area subpostrema. A region adjacent to the area postrema in the cat.

AbstractA region in the medulla oblongata of the cat, which has been named the area subpostrema, has been described. This area is unique in demonstrating strong staining for both specific and pseudocholinesterase in the walls of capillaries and also in an arc of neuropil which partly surrounds these capillaries. Over most of its length the area subpostrema lies immediately ventral or ventrolateral to the area postrema, dorsal to the dorsal motor nucleus of the vagus and dorsomedial to the tractus solitarius. The area subpostrema, unlike the area postrema, is not stained by the vital dye trypan blue. A group of capillaries in the inferior olivary nucleus which demonstrate specific but not pseudocholinesterase activity have also been described.Using Nissl stains and silver impregnation techniques the area subpostrema has been found to contain a few small neurones and many unmyelinated nerve fibers. Some nerve fibers within the area subpostrema demonstrate specific cholinesterase activity.The relation of the area subpostrema to the nucleus of the tractus solitarius has been discussed. It has been suggested that the area subpostrema might have receptor functions related to autonomic control.

Cholinesterase and pseudocholinesterase activity in blood of rats during ontogenesis

Cholinesterase and pseudocholinesterase activity in blood of rats during ontogenesis

Serum proteins in human trichinosis

Of 200 patients suffering from trichinosis, the course of the disease was mild in one hundred, moderate in sixty-six and severe in thirty-four. The following laboratory tests were performed serially: serum total protein and its electrophoretic pattern, thymol turbidity, serum pseudocholinesterase activity and serologic tests (i.e., complement fixation and precipitation). Proteinuria was estimated by the tannin method. The greatest decrease in serum total protein, especially albumin, was found in the fourth and fifth week of the disease and was related to its severity. Proteinuria was also more prominent in severe cases of trichinosis. A relative and absolute increase in gamma globulins paralleled the increased titer of serologic tests and abnormal thymol turbidity test. In thirty-five persons, follow-up examinations were made within one to twenty months after discharge and almost complete normalization of the previously abnormal tests was found.

Atypical pseudocholinesterase activity: a review and presentation of two cases.

1. The method of Kalow and Genest for the determination of the dibucaine number on patient sera identifies the presence of atypical pseudoCholinesterase activity. 2. The usual type of pseudoCholinesterase, or an atypical variety of the enzyme, or a mixture of the two may exist in any one individual. Low pseudoCholinesterase activity of the usual or normal type is associated with a variety of disease states, while atypical pseudoCholinesterase activity is genetically determined. 3. Tests for levels of pseudoCholinesterase including determination of the dibucaine number should be conducted on all family members of any patients who have had prolonged apnoea following a single dose of succinylcholine and whose dibucaine number has been shown to be abnormally low. All patients with dibucaine numbers in the intermediate and abnormal range should be regarded as potential candidates for prolonged apnoea after succinylcholine. These people should be given cards to carry which should be presented on the occasion of any admission to hospital. 4. Genealogical trees of two families exhibiting the presence of atypical pseudoCholinesterase activity are shown.

Echothiophate Iodide Treatment of Glaucoma in Pregnancy

A glaucomatous patient treated with echothiophate iodide subsequently became pregnant. The drug was withdrawn at 32 weeks because of unknown fetal hazards. A month before delivery a right anterior sclerotomy and peripheral irridectomy were performed under general anesthesia avoiding succinylcholine chloride, with its known aphoea risk, as muscle relaxant. The pseudocholinesterase activities of both mother and infant were assayed at intervals after delivery. The results suggest that echothiophate iodide had traversed the placental barrier and caution is indicated in its future use in such cases.

Histochemical localization of esterase activity in schistosomes

Acetylcholinesterase and pseudocholinesterase activities were demonstrated in adult Schistosoma haematobium, S. mansoni, and S. rodhaini with wide-spectrum substrates associated with specific inhibitors. Only acetylcholinesterase activity was detected in the free-living larval stages. The results were confirmed by using specific substrates. No nonspecific esterases were detected. The specific inhibitor of mammalian acetylcholinesterase, 62C47, was only partially inhibitory to the parasite enzyme.

A histochemical study of the esterases in the bladder of the toas ( Bufo marinus)

1. 1. Histochemical localization has confirmed that the toad bladder contains both true and pseudo-cholinesterases as well as non-specific esterases. The true cholinesterase appears to ne an acetylcholinesterase. 2. 2. The majority of intramural nerves stain intensely for true cholinesterase, which is consistent with previous evidence that the autonomic innervation is predominantly cholinergic. 3. 3. True cholinesterase is also localized in mucus-containing goblet cells of the mucosa and within the muscle bundles. 4. 4. Low pseudo-cholinesterase activity is associated with the muscle bundles and with intramural nerves. 5. 5. Non-specific esterase activity is confined to the mucosal epithelium, blood vessel endothelium and scattered goblet cells. 6. 6. In comparison to results reported in the literature for mammalian tissues, the non-specific esterase substrate α-naphthyl acetate is not readily hydrolysed by the true cholinesterase of the toad bladder.

Diagnostic value of liver function tests and Entamoeba histolytica antibody studies in East Africans.

Liver function tests and Entamoeba histolytica (E.H.) antibody titres have been studied in a variety of tropical and liver diseases. Patients with hepatic amoebiasis had a raised E.H. antibody titre and tended to have a low pseudocholinesterase activity. In two cases of amoebic liver abscess, which were treated by aspiration and emetine, there was a remarkable drop in the E.H. antibody titre. In a number of other hepatic and tropical conditions the E.H. antibody titre was not significantly raised and the liver function tests were typical of the various conditions studied.

Qualitative defects of pseudocholinesterase activity.

Qualitative defects of pseudocholinesterase activity.

A Clinical and biochemical approach to cholinesterase problems in anaesthesia

Pseudocholinesterase is essential for the rapid breakdown of succinylcholine. If pseudocholinesterase is quantitatively or qualitatively deficient, prolonged apnoea may result after administration of succinylcholine. Normal pseudocholinesterase activity is dependent upon allelic genes Eiu. There now appear to be two atypical variant alleles and a silent allele. In anaesthetic practice the homozygous atypical pseudocholinesterase variants may be expected to be encountered with a frequency of about 1:3000.

Uncommon electrophoretic patterns of serum cholinesterase (pseudocholinesterase).

HARRIS et al.1 used two-dimensional electrophoresis on filter paper and in starch gel to show that serum cholinesterase is made up of several electrophoretically separable components. After completion of the runs, four zones of pseudocholinesterase activity were found in the gels, corresponding to at least four isozymes which are called C1, C2, C3 and C4. The last is the slowest component, in which most of the pseudocholinesterase activity is localized.

EFFECT OF THE THYROID GLAND ON PSEUDOCHOLINESTERASE ACTIVITY IN THE LIVER AND SERUM OF THE RAT

ABSTRACT The effect of the thyroid gland on the pseudocholinesterase activity has been investigated. Whereas in female rats the pseudocholinesterase activity is not affected by thyroidectomy, the activity in the liver and serum of male rats is significantly increased after thyroidectomy. In castrated and thyroidectomized male rats, the pseudocholinesterase activity markedly exceeds that of either the castration or the thyroidectomy level; the effects are additive and independent In female rats, thyroidectomy causes an increase of pseudocholinesterase activity in spayed animals. Administration of thyroxine is followed by a decrease in the pseudocholinesterase activity of castrated-thyroidectomized males. It is concluded that the thyroid gland as well as the gonads control the pseudocholinesterase activity: in male rats the relatively low pseudocholinesterase activity is maintained by the combined actions of the gonads and the thyroid gland, whereas in female rats, the thyroid gland does not affect the relatively high enzyme activity induced by the ovarian oestrogens.

Further tests on the phylogenetics of pseudocholinesterases

Studying phylogenetics of pseudocholinesterase in sera of various species, we obtained the following results by applying different biochemical methods: spectrophotometrie assay, agargel-diffusion-test, agar-gel-electrophoresis, immnno-electrophoresis, starch-gel-electrophoresis, immunotitration and immune-absorption-test. a) Interspeciesvariability. Immunologieally there are evident differences between sera of primates and other species. The primates homo, macaeus, pan and hylobates cannot be differentiated by stareh-gel-electrophoresis, whereas the other primates show various pattern of esterases. High pseudocholinesterase activity is observed in the sera of homo, pan and maeacus, while the sera of eercopithecus aethiops show low activity, while ovis, sus, bos, mus, and ]epus are almost inactive. Agar-gel-diffusion-test and starch-gel-electrophoresis gave us no further information for the characterisation of the proteins of different species. b) Intraspeciesvariability. Intraspecieswri~bilities could be shown in sera of pan and macacus. Atypical data in sera of pan were obtained by spectrophotometrical methods (activity, DN, FN) and by immunotitration. Some sera of macac~ mulatta (Rhesus) behaved differently in agar-gel-diffusion-test and starch-gel-electrophoresis.

Effect of androgenic and anabolic compounds on pseudocholinesterase activity in the liver and serum of the rat.

ABSTRACT Immature male and female rats have a similar basal level of pseudocholinesterase activity in the liver and serum. In male rats pseudocholinesterase activity declines sharply with the onset of sexual maturity, between the fourth and the fifth week, after which it remains more or less constant. In female rats, also coinciding with the onset of sexual development, the activity starts to rise between five and six weeks and then increases gradually up to twenty weeks. Castration of male rats results in an increase of the enzyme activity to the basal level, whereas subsequent injection of testosterone-propionate brings about a fall to the level found in adult male rats. Three androgenic/anabolic steroids were compared for their effects on pseudocholinesterase activities in liver and serum of male castrates, viz. testosterone-propionate, testosterone-phenyl-propionate and nor-testosterone-phenyl-propionate, the latter known to possess a relatively high anabolic potency. This was confirmed in our experiments by direct protein determinations in liver and serum and by levator ani muscle/seminal vesicle ratios. At a dose of 1 mg daily for ten days, the former two substances had a similar considerable effect on pseudocholinesterase activity, whereas the effect of the nor-derivative was much smaller. A response similar to that of one milligram of testosterone-propionate was only obtained with 4 mg of the nor-derivative. At that dose level the androgenic effect of the nor-derivative on the seminal vesicles is somewhat less than that of 1 mg testosterone-propionate daily. It is concluded that the cholinesterase activity lowering effect of the compounds investigated is correlated with their androgenic rather than with their anabolic potencies.