Manual Colorimetric Methods for Pseudocholinesterase and Red Cell (True) Cholinesterase

MacQueen, J.; Plaut, David; Borges, João Pedro Moraes; Anido, G

doi:10.1093/clinchem/17.6.481

Cited by 19 publications

(9 citation statements)

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“…gesting an approximate KI (inhibitor constant) of 5 X Specificity is not conferred by substrate (acetylthiocho-M. At M, there was a marked increase in line iodide) seIection alone [12]. The following profde OD, which was entirely due to the edrophonium reagent can be deduced from the use of inhibitors.…”

Section: Consideration Of Variablesmentioning

confidence: 94%

Acetylcholinesterase in the human erythron. II. Biochemical assay

1988

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Acetylcholinesterase (AChE) is an integral erythrocyte membrane protein. A role for the enzyme in the developing human erythron is being explored. Assays of AchE by the standard Ellman technique overestimate the amount of enzyme by failing to account for the contribution of hemoglobin to the optical density of the reaction mixture. Furthermore, reliance on substrate selection alone for specificity is unsatisfactory. Incorporation of inhibitors of "true" AchE and of pseudocholinesterase confer greater ability to distinguish one enzyme from the other. In our experience, the inhibitor constant (Kl) for edrophonium, which is highly specific for AChE, is approximately 5 x 10(-5) M against adult human erythrocytes that contain significantly more total cholinesterase activity than do erythrocytes from umbilical cord blood. This consists of both "true" and "pseudo" enzyme, the former predominating and accounting for 0.75-1.65 (mean 1.02, median 0.87) femtomoles of substrate hydrolysed per min per cell in adult blood, with values of 0.15-1.04 (mean 0.71, median 0.73) obtained on cord blood. Moreover, the enzyme activity in neonatal erythrocytes has a rather different inhibitor profile from that of adult cells. AChE was also demonstrated in fresh (ALL) and cultured (K562 and HL60) human leukemic cells, as well as in primitive granulocyte-macrophage and erythroid cells cloned from normal human bone marrow. In the erythroid colonies the enzyme activity was 0-3.76 (mean 1.20, median 0.76) femtomoles per min per cell, apparently the first successful measurement of AChE in such cells.

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Section: Consideration Of Variablesmentioning

confidence: 94%

Acetylcholinesterase in the human erythron. II. Biochemical assay

1988

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“…Measurements on complete blood cell counts, routine blood biochemistry and urinalysis were conducted to rule out systemic diseases which could affect reproductive function. Erythrocyte true cholinesterase activity (E-ChE) was measured to assess the exposure to organophosphorus (OP) insecticides by an improved version of Garry and Routh's modification of Ellman's method 31) . This study was conducted according to the Declaration of Helsinki; signed informed consent was obtained from all the subjects, and the study protocols were reviewed and approved by the ethical committee of Nagoya University Graduate School of Medicine.…”

Section: Reproductive Health Check-upsmentioning

confidence: 99%

A Survey of Semen Indices in Insecticide Sprayers

Kamijima

Hibi

Gotoh

et al. 2004

Journal of Occupational Health

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A Survey of Semen Indices in InsecticideSprayers: Michihiro Kamijima, et al. Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine-This study aims at clarifying the semen indices of insecticide sprayers who are exposed mainly to organophosphorus and pyrethroid insecticides. Eighteen male sprayers out of 54 working for 9 companies in central Japan and 18 age-matched students or medical doctors as unexposed controls participated in detailed reproductive check-ups conducted in summer and the following winter. The sprayers were exposed to insecticides more in summer, the busiest season, than winter, the off-season (p<0.05). Erythrocyte true cholinesterase activities in the sprayers were lower than in the controls in summer (p<0.05), and decreased in significant association with the increase in exposure frequency. Testicular volumes in the sprayers tended to be smaller than in the controls (p=0.06). The serum testosterone concentration in winter in the sprayers was higher than in the controls (p<0.05), though luteinizing h o r m o n e a n d f o l l i c l e s t i m u l a t i n g h o r m o n e concentrations were not significantly different. The sperm counts and vitality were comparable between the groups, but detailed sperm motility analysis in summer revealed that the percentages of slow progressive and nonprogressive motile sperm were twice as high in the sprayers (p<0.05), and that of rapid progressive sperm tended to be lower (p=0.06). Such differences were not observed in winter. Differential sperm morphology counts showed that interaction of group and abstinence effects were significant in sperm Received Aug 19, 2003; Accepted Nov 28, 2003 Correspondence to: M. Kamijima, Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan (e-mail: kamijima@med.nagoya-u.ac.jp) with normal morphology and with head deformity only in the summer check-up. Despite possible inherent differences between the groups, the above seasondependent differences suggested that the observed lower semen quality in the sprayers was associated with pesticide spraying work.

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“…A widely used method for determining cholinesterase activities is the spectrophotometric method of Ellman et al 16 with thiocholine esters as substrates and DTNB as the thiol reagent forming the yellow dianion TNB. The method has repeatedly been modified in order to meet requirements for different applications with the use of different thiocholine esters and the phosphate buffer as reaction medium in these assays 17,19,[23][24][25] . Maximum activity of the enzyme is obtained for pH 8.5-9.0 with butyryl thiocholine substrate at 37°C.…”

Section: Discussionmentioning

confidence: 99%

“…Intra-day CV values for AChE activity were 1.20% and MacQueen et al 23 Brogdon 24 Reiner et al 25 Ellman et al 16 Proposed method 2).…”

Section: Precision Of Assaymentioning

confidence: 96%

Simple and rapid colorimetric method for determination of erythrocyte and plasma cholinesterase activities and comparison with the standard Ellman’s method

Patel

2023

Public Health Toxicol

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Manual Colorimetric Methods for Pseudocholinesterase and Red Cell (True) Cholinesterase

Cited by 19 publications

References 0 publications

Acetylcholinesterase in the human erythron. II. Biochemical assay

Acetylcholinesterase in the human erythron. II. Biochemical assay

A Survey of Semen Indices in Insecticide Sprayers

Simple and rapid colorimetric method for determination of erythrocyte and plasma cholinesterase activities and comparison with the standard Ellman’s method

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