Normal Cholinesterase Activity Research Articles

Effects of altered gravity induced by clinorotation on the cholinesterase activity of the non-sentient model Paramecium primaurelia (Protozoa)

Compounds known as chemical mediators, including acetylcholine, have been found not only in humans and animals, but also in living organisms, like protozoa, which lack nervous system. In Paramecium primaurelia has been described a cholinergic system, which is proven to play an important role in cell-cell interactions during its developmental cycle. In our work we investigated the effects of exposure to simulated microgravity (3D Random Positioning Machine, 56 rpm, 10-6 g) on the cholinesterase activity of the eukaryote unicellular-organism alternative-model P. primaurelia. Our results show that the exposure of P. primaurelia to microgravity for 6 h, 24 h, 48 h affects the localization and the amount of cholinesterase activity compared to cells grown under Earth gravity conditions (1 g). However, these effects are transient since P. primaurelia restores its normal cholinesterase activity after 72 h under microgravity conditions, as well as cells exposed up to 72 h to microgravity and then placed under terrestrial gravity for 48 h.

Cholinesterase Activity on Palm Oil Plantation Workers in Parenggean, Kotawaringin Timur

Use of pesticide is widely used in palm oil plantation industry. Pesticide exposure can affect pesticide-spraying workers' health. This study aimed to determine acetylcholinesterase enzyme (AChE) activity levels and identify of poisoning risk factors on pesticide-spraying workers in a palm oil plantation Comanditaire Venootschap (CV) unit in Parenggeran, Kotawaringin Timur, Central Kalimantan. The cross-sectional study design was conducted to examine cholinesterase enzyme activity levels on 15 pesticide-spraying workers. The cholinesterase levels were measured using an automated photometric technique. This study found that all workers have normal cholinesterase activity levels. The average cholinesterase activity levels were 7065,36 U/L and 6528 U/L, respectively for male and female workers. It was also found that two male workers cholinesterase activity levels of using glyphosate pesticide were almost close to the lower limit of the normal levels range, 4720 U/L, and 4958 U/L, respectively. Use of Personal Protective Equipment (PPE) during the pesticide spraying and maximum time allowed of pesticide spraying in a day have to be considered as an important rule to avoid excessive pesticide exposure.

Lambert-Eaton myasthenia

The myasthenic syndromes are a group of disorders in which neuromuscular transmission is impaired at the motor endplate. Many of the myasthenic syndromes are congenital, but Lambert-Eaton myasthenic syndrome, which was one of the fi rst of these syndromes to be described, is associated with a tumour, mostly small-cell carcinoma of the lung, in 50–60% of patients. In 1951, severe muscle weakness was seen in a patient with bronchial neoplasm who was admitted to St Thomas’s Hospital, London, UK; this weakness disappeared almost immediately after removal of the tumour, suggesting that such neoplasms might give rise to a peripheral neuropathy. When a 47-year-old man complaining of progressive muscle weakness that fi rst aff ected his legs but later aff ected his arms and head was admitted to the same hospital 2 years later, further investigations were warranted. Upon examination, he was found to have small-cell lung carcinoma, and administration of thiopentone sodium and succinylcholine prior to biopsy led to prolonged apnoea. In the presence of normal cholinesterase activity, this was suggestive of a change in the response of the motor endplate to depolarising drugs, and investigations showed that the response at the motor endplate to tubocurarine, decamethonium, and succinylcholine was similar to that seen in myasthenia gravis. At the meeting of the American Physiological Society in 1956, Lambert, Eaton, and Rooke presented the cases of six patients with defective neuromuscular transmission that was associated with malignant neoplasms. In these patients, many of the clinical and electrophysiological features were reported to be diff erent from those seen in myasthenia gravis. A year later, Lambert and Eaton reported the electrophysiological features of the myasthenic syndrome, leading to the eponym.

Characterisation of cholinesterases and evaluation of the inhibitory potential of chlorpyrifos and dichlorvos to Artemia salina and Artemia parthenogenetica.

In this study, the acute toxicity of the organophosphorous pesticides dichlorvos and chlorpyrifos to two different species of Artemia (A. salina and A. parthenogenetica) was evaluated. In addition, the in vivo effect of these two pesticides on cholinesterase (ChE) activity of both A. salina and A. parthenogenetica was also determined. The characterisation of the ChE, using different substrates and specific inhibitors, and the normal range of activity in non-exposed individuals were previously investigated for both species. The results obtained indicate that the ChE of A. salina is different from that of A. parthenogenetica and that both enzymes cannot be classified neither as acetylcholinesterase nor as butyrylcholinesterase since they show intermediary characteristics between the two vertebrate forms. The range of normal ChE activity was 2.65+/-0.15 U/mg protein for A. salina, and 3.69+/-0.17 U/mg protein for A. parthenogenetica. Significant in vivo effects of both pesticides on Artemia ChE activity were found, at concentrations between 5.38 and 9.30 mg/l for dichlorvos and between 1.85 and 3.19 mg/l for chlorpyrifos. Both Artemia species are resistant to these pesticides and they are able to survive with more than 80% ChE inhibition. However, A. parthenogenetica is more resistant than A. salina, with about a 95% reduction in its ChE activity respect to the control for nauplii exposed to the median lethal concentrations (LC50), without lethal effects after 24 h of exposure.

The relationships between brain, serum, and whole blood ChE activity in the wood mouse (Apodemus sylvaticus) and the common shrew (Sorex araneus) after acute sublethal exposure to dimethoate

Abstract Inhibition of cholinesterase (ChE) activity produced by a single acute intraperitoneal administration of dimethoate was studied in the wood mouse, Apodemus sylvaticus, and the common shrew, Sorex araneus, under laboratory conditions. ChE values from serum and whole blood were compared with those obtained from brain in order to obtain a non-destructive tool for predicting the severity of brain acetylcholinesterase (AChE) inhibition. In addition, serum and brain inhibition following oral exposure to dimethoate was also measured in the wood mouse. Normal ChE activity was higher in the brain and whole blood of the shrews than in wood mice. There was no difference between species in serum ChE activity. Exposure to dimethoate caused a dose-dependent reduction in ChE activity and there was a significant recovery in activity with increasing time after administration. In both species, serum and whole blood were more sensitive than brain for revealing organophosphate-induced ChE inhibition and serum was more sensitive than whole blood. Statistically significant relationships were defined between whole blood and brain ChE activity and between serum and brain ChE activity. Compared with serum, whole blood ChE activity was the more accurate predictor of brain AChE levels. The relationships between brain and serum ChE activity did not appear to be affected by the route of administration of the pesticide.

Changes in Plasma Cholinesterase Activity and Mivacurium Neuromuscular Block in Response to Normothermic Cardiopulmonary Bypass

The effect of reduced plasma cholinesterase (ChE) activity in response to normothermic cardiopulmonary bypass (CPB) on mivacurium neuromuscular block was studied in nine patients anesthetized with propofol/fentanyl. Mivacurium was injected intravenously as an initial bolus of 150 micrograms/kg; repeat doses of 75 micrograms/kg were given when the evoked twitch tension attained 75% of control. With the institution of CPB, the previously normal ChE activity was reduced by 42% and remained low until the end of the procedure. The times of onset (time from the end of injection to maximum neuromuscular block) of the maintenance doses of mivacurium were 26% longer during than before or after CPB (P < 0.05). Their DUR25% (time from end of injection to recovery of neuromuscular transmission to 25% of control) were 13 +/- 3 min (means +/- SD) before, 14 +/- 4 min during, and 16 +/- 4 min (P < 0.05) after CPB. It is concluded, that, although markedly reducing the patient's previously normal ChE activity, normothermic CPB had little effect on the time characteristics of mivacurium neuromuscular block.

Recovery of train-of-four after mivacurium.

The present study was designed to determine the time-course of recovery of the train-of-four (TOF) ratio during spontaneous recovery from mivacurium-induced block. Fifteen patients, free of neuromuscular disease, undergoing general endotracheal anaesthesia with isoflurane were studied. After anaesthetic induction, patients received a bolus dose of mivacurium 0.15 mg.kg-1. The TOF was then recorded continuously every 12 sec with a mechanogram (adductor pollicis monitor). When the TOF ratio recovered spontaneously to 0.9, an additional 0.05 mg.kg-1 of mivacurium was given. The durations required for recovery from a TOF ratio of 0.3 to 0.7 (DUR0.3-0.7) and from a TOF ratio of 0.3 to 0.9 (DUR0.3-0.9) were determined. The DUR0.3-0.7 averaged 7.0 +/- 2.5 min (range 3.4-12.2 min). The DUR0.3-0.9 averaged 11.8 +/- 3.9 min (range 6.0-20.2 min). There was no evidence of prolongation of recovery times (cumulation) following repeated dosing. The present data indicate that, in patients with normal cholinesterase activity (clinical duration 7-25 min), waiting 20 min beyond the time when fade is no longer apparent by visual or tactile evaluation is sufficient to attain a TOF ratio greater than 0.7-0.9 during spontaneous recovery from mivacurium, and may enable anaesthetists to avoid antagonism of mivacurium-induced block.

Inverse relationship between serum cholinesterase activity and the administration of cyclophosphamide: an Index of cyclophosphamide therapy

To determine whether serum cholinesterase activity can be a monitoring index of cyclophosphamide therapy in patients with steroid-resistant glomerulopathy, we compared the cholinesterase activity of 37 patients who received a combined therapy that included the use of cyclophosphamide, prednisolone, antiplatelet drugs, and anticoagulant drugs, with the cholinesterase activity of 25 patients who received prednisolone therapy that excluded cyclophosphamide from the combined therapy. In the prednisolone and the combined groups, cholinesterase activity declined as shown in the following formula: Y = 371-26.4 x log(X): (r2 = 0.28), Y = 444-147.7 x log(X): (r2 = 0.95), respectively. (Y: cholinesterase activity, X: the day after treatment). In the combined therapy group, the prevalence of adverse reactions following treatment in the subgroup below 200 U/l of cholinesterase activity was significantly greater (P < 0.01) than that in the subgroup above 200 U/l of cholinesterase activity. However, there was no significant difference (P < 0.25) in the prevalence of adverse reactions between the subgroups with more or less than 184 U/l of cholinesterase activity following treatment. These results suggest the importance of not going below 200 U/l of cholinesterase activity after treatment when the normal cholinesterase activity range is between 300 and 760 U/l (e.g. less than 65% of the lowest value of the normal range of other hospitals) in order to eliminate the hazards of cyclophosphamide to the patients with steroid-resistant glomerulopathy.

Acute toxicity studies with quinuronium sulfate in laboratory animals and sheep

The acute toxicity of quinuronium was investigated by measurements of lethal doses (LD 50) in mice and rats, cholinesterase activity in vivo in whole blood, and protection from anticholinesterase activity by atropinisation in sheep and rabbits. The LD 50 s in mice injected i.p. and s.c. were 4.80 and 5.40 mg kg and in rats 6.3 and 6.5 mg kg for i.p. and s.c. routes, respectively. Signs of salivation, defecation, anorexia and muscular spasms were observed in sheep. In rabbits anorexia and depression only were observed. There was species variation in normal cholinesterase activity, rabbits being low in activity. Quinuronium inhibited cholinesterase activity from 10 min to 24 h after treatment in sheep by 24% of the normal baseline values. The enzyme activity returned to normal at 48 h. Atropinisation partially protected against anticholinesterase activity in sheep; cholinesterase activity was inhibited by only 14% of the normal baseline values 10 min to 2 h after treatment. This study indicates that quinuronium is highly toxic and that rabbits are moderately resistant.

Carbaryl residues in tissues and cholinesterase activities in brain and blood of rats receiving carbaryl

The diagnostic value of measuring insecticide levels and cholinesterase activity in carbaryl-poisoned rats was studied. Mature, male rats received 450, 800, or 1200 mg carbaryl/kg orally, and carbaryl residues in liver, heart, and brain and/or cholinesterase (ChE) activity in brain, red blood cells, and plasma of sacrificed, moribund, and dead rats were compared. Significant tissue residues were still present 24–48 hr after dosing. The lowest liver, heart, and brain carbaryl levels were 11.7, 3.6, and 5 ppm, respectively, in fatally poisoned rats. The brain ChE activity of fatally poisoned rats was less than 35% of normal, while surviving rats had greater than 55% of normal ChE activity 48 hr after dosing. Following dosing, red blood cells and plasma ChE activity was near 30% of normal. Cholinesterase activity in brain, red blood cells, and plasma was back to 70% of normal 96 hr after dosing. Blood studies on gastrointestinal tract absorption of carbaryl indicated that prolonged absorption may account for extended clinical signs observed. Whole blood was superior to plasma for carbaryl determination.

Recovery of brain and plasma cholinesterase activities in ducklings exposed to organophosphorus pesticides

Brain and plasma cholinesterase (ChE) activities were determined for mallard ducklings (Anas platyrhynchos) exposed to dicrotophos and fenthion. Recovery rates of brain ChE did not differ between ducklings administered a single oral dose vs. a 2-week dietary dose of these organophosphates. Exposure to the organophosphates, followed by recovery of brain ChE, did not significantly affect the degree of brain ChE inhibition or the recovery of ChE activity at a subsequent exposure. Recovery of brain ChE activity followed the general model Y = a + b(logX) with rapid recovery to about 50% of normal, followed by a slower rate of recovery until normal ChE activity levels were attained. Fenthion and dicrotophos-inhibited brain ChE were only slightly reactivated in vitro by pyridine-2-aldoxime methiodide, which suggested that spontaneous reactivation was not a primary method of recovery of ChE activity. Recovery of brain ChE activity can be modeled for interpretation of sublethal inhibition of brain ChE activities in wild birds following environmental applications of organophosphates. Plasma ChE activity is inferior to brain ChE activity for environmental monitoring, because of its rapid recovery and large degree of variation among individuals.

Insecticidal action of carbamates on the eggs of the house cricket.

Embryonic development of Acheta domesticus (L.) took 9 days at 35°C. When eggs were dosed with carbaryl or propoxur 3-8 days after deposition, development was normal, and no mortality occurred. Eggs dosed at day 1 or 2 were killed immediately, but this mortality could be caused by the lethal effects of the carrier (DMSO). Cholinesterase (ChE) activity was recorded first at day 4 and increased to maximum embryonic levels by day 7, increasing only slightly at hatching. Carbamates when applied 3-8 days after deposition caused an immediate decrease in the ChE activity level without initiating mortality. ChE activity levels tended to return to normal within 3 days after dosage. Eggs when dosed with carbaryl at Day 3 had a higher ChE activity at hatching than did undosed controls. Pretreatment of eggs did not change the susceptibility of the nymphs to anticholinesterases in most cases. However, nymphs with a ChE activity level higher than normal at hatching (dosed with carbaryl at Day 3) were less susceptible to anticholinesterase agents than were nymphs with a normal ChE activity level.

Bioassay and histochemical studies of the poisoning and recovery of house-flies (Musca domestica L.) treated with diazinon and diazoxon.

Newly emerged and 3-day-old house-flies (Musca domestica L.) of a diazinin-susceptible and a diazinon-resistant strain were treated topically with diazinon or diazoxon and examined for symptoms of poisoning and recovery at intervals up to 5 hours and at 24 hours after treatment. The effects of the poisons varied with the age and strain of the flies and with the poison used. Most of the flies that became paralysed died, but some recovered, even after appearing to be dead. Of flies treated when newly emerged, more of the resistant than of the susceptible strain recovered from paralysis, and more recovered from diazoxon than from diazinon treatment. Recoveries were fewer amongst flies treated when three days old and occurred in appreciable numbers only amongst those of the resistant strain treated with diazoxon.Histochemical tests on flies, treated with diazoxon showed a close correlation between inhibition of cholinesterase activity in the thoracic ganglion and the external symptoms of poisoning. Inhibition was slight in apparently unaffected flies, more extensive in severely affected flies, and total or nearly so in completely paralysed flies. Inhibition first appeared at the periphery of the ganglion and spread inwards to the centre. Flies that recovered from paralysis had normal or almost normal cholinesterase activity, partially recovered flies showed activity only in the central parts of the ganglion. Recovery of cholinesterase activity seems to occur from the centre of the ganglion outwards.

BLOOD CHOLINESTERASE LEVELS IN ORGANIC PHOSPHATE INTOXICATION.

The inhibition of cholinesterase (ChE) activity by the organic phosphate insecticides provides a sensitive indicator of absorption of these compounds. In order to interpret the laboratory results of the ChE activity, one must consider several factors, including the accuracy of the determination. Unless the laboratory personnel are accustomed to performing the analysis (Michel method), a duplicate sample should be sent to a laboratory where the test is commonly done for comparison. Blood is collected in a heparinized capillary tube, and the plasma and red blood cells (RBC) are separated as soon as possible. The test may be performed with as little as 0.02 ml of heparinized blood. 1 Since there is a 100% variation in the normal ChE activity among different individuals, and since the same person may show a variation of as much as 25% at different times, it is extremely helpful if the normal values for the individual

STUDIES ON CHOLINESTERASE OF LABYRINTHINE AND SPINAL FLUID

Part I In spite of the recent development of the chemical substance theory on nerve impulse, very few biochemical investigations have been reported on the cochlear response.The author studied the Cholinesterase (ChE) activity of the labyrinthine fluid of guinea-pigs by Conway's microdiffusion analysis.The results obtained were as follows, 1. ChE in the labyrinthine fluid, both that in endolymph and perilymph, was specific Choli-nesterase.2. ChE activity of endolymph was about 4.36 times as much as that of perilymph. Free acetic acid produced from acetylcholine by 1mg endolymph in 40minutes at 38° was 0.0183mg% and by 1mg perilymph, 0.0042mg%.3. The injection of 2% Quinine hydrochloride solution (0.05gr per kg.) decreased gradually the ChE activity of endolymph and perilymph in parallel, but the diminution was slow and small in comparison with other cases.4. The injection of Dihydrostreptomycin (0.4g per kg) decreased the ChE activity more remarka-bly and earlier than the case of Quinine. The diminution of ChE activity of perilymph was more remarkable than that of endolymph.5. The sound stimulation (3000 cps 90db) for 60 hours diminished markedly the ChE activity of labyrinthine fluid and that of endolymph as if inhibited completely.Without stimulation for 7 days after 60 hours stimulation, the ChE activity of endolymph was recovered remarkably, but that of perilymph still remained low.In case of the experiment of repeated 12 hours stimulation and 7 day nonstimuration, the dimi-nution of ChE activity of labyrinthine fluid was slight.Part II The author carried out the clinical experiments on the ChE activity of spinal fluid by Hesterin's method with Beckman's spectrophotometer.The results obtained were as follows.1. Normal ChE activity was 0.175±0.006 ElogIo/I in equilibrium at range λ500mμ, the upper limit was 0.200, and the lower limit was 0.140.2. In 11 cases of conductive deafness, the ChE activities were normal or slightly below normal value except 2 cases of otitis media exsudativa acuta (0.200, 0.210).3. In 19 cases of nerve deafness, a considerable diminution of ChE activity was observed except 2 cases. Especially, in deafness due to detonation, sudden, traumatic, streptomycin, Menier's syndro-me, following to cerebral abscess, Congenital deafmutism, the ChE activity decreased remarkably.Two cases of Cholesteatoma-deafness and nerve deafness with central retinitis showed normal value.

Normal Cholinesterase Activity in the Erythrocytes of Cattle

Fourteen groups of beef and dairy cattle belonging to Clemson College were employed in this experiment. A total of 75 animals were represented with 160 blood samples taken. At least two and usually three or four determinations were conducted on each sample for erythrocyte cholinesterase enzyme activity. The electrometric method with the stated modifications was the basic method employed in determining the cholinesterase activity. (Michel 1949.) It appears that variations in ambient temperature have no effect on bovine cholinesterase activity. The mean for beef cattle was found to be delta pH/hr. 0.434 and for dairy cattle delta pH/hr. 0.410. Although the dairy cattle mean was slightly lower than the mean of beef cattle, it was not significant at the 5% level of probability. The mean for the 14 groups of beef and dairy cattle was found to be delta pH/hr. 0.422 with its confidence limits of ± 0.074.