Automated discrete kinetic method for erythrocyte acetylcholinesterase and plasma cholinesterase.

1981 ◽  
Vol 27 (6) ◽  
pp. 926-929 ◽  
Author(s):  
P J Lewis ◽  
R K Lowing ◽  
D Gompertz
Keyword(s):  
Cholinesterase Activity ◽  
Kinetic Method ◽  
Colorimetric Method ◽  
Acetylcholinesterase Activity ◽  
Plasma Cholinesterase ◽  
Organophosphate Pesticides ◽  
Plasma Cholinesterase Activity ◽  
Quinidine Sulfate

Abstract We describe an automated kinetic method for erythrocyte acetylcholinesterase (EC 3.1.1.7) and plasma cholinesterase (EC 3.1.1.8) based on Ellman's colorimetric method. Quinidine sulfate is used as an inhibitor of plasma cholinesterase during the measurement of erythrocyte acetylcholinesterase activity, obviating the need for washing the erythrocytes before lysis. Results by this method are compared with those obtained by the electrometric delta pH method of Michel. To emphasize the need for measuring both erythrocyte acetylcholinesterase and plasma cholinesterase activity in workers exposed to organophosphate pesticides, we present a study of serial activities of both enzymes in a person accidentally exposed to demeton-S-methyl.

Potentiation of Mivacurium Blockade by Low Dose of Pancuronium

2003 ◽  
Vol 98 (5) ◽  
pp. 1057-1062 ◽  
Author(s):  
Cyrus Motamed ◽  
Riad Menad ◽  
Robert Farinotti ◽  
Krassen Kirov ◽  
Xavier Combes ◽  
...  
Keyword(s):  
Acetylcholine Receptors ◽  
Low Dose ◽  
Cholinesterase Activity ◽  
Plasma Concentrations ◽  
Orotracheal Intubation ◽  
Plasma Cholinesterase ◽  
Neuromuscular Blocking ◽  
Pharmacokinetic Analysis ◽  
Plasma Cholinesterase Activity ◽  
Before And After

Background Mivacurium is potentiated by pancuronium to a much greater extent than other relaxants. In a previous investigation we suggested that this potentiation could be due to the ability of pancuronium to inhibit plasma cholinesterase activity, but we did not measure plasma concentrations of mivacurium. In the current study we performed a pharmacokinetic analysis by measuring the plasma concentration of mivacurium when preceded by administration of a low dose of pancuronium. Methods After induction of general anesthesia with propofol and fentanyl and orotracheal intubation, 10 patients (pancuronium-mivacurium group) received 15 microg/kg pancuronium followed 3 min later by 0.1 mg/kg mivacurium, whereas 10 other patients (mivacurium group) received saline followed by 0.13 mg/kg mivacurium 3 min later. Plasma cholinesterase activity was measured before and 3 and 30 min after pancuronium dosing in the pancuronium-mivacurium group and was measured before and after administration of saline in the mivacurium group. Arterial plasma concentrations of mivacurium and its metabolites were measured at 0.5, 1, 1.5, 2, 4, 10, 20, and 30 min after injection. Neuromuscular blockade was assessed by mechanomyography. Results Plasma cholinesterase activity decreased by 26% in the pancuronium-mivacurium group 3 min after injection of pancuronium (P < 0.01) and returned to baseline values 30 min later; however, no significant variation was observed in the mivacurium group. The clearances of the two most active isomers (Cis-Trans and Trans-Trans) were lower in the pancuronium-mivacurium group (17.6 +/- 5.1, 14.7 +/- 5.3 ml. min-1. kg-1, respectively) than in the mivacurium group (32.4 +/- 20.2, 24.8 +/- 13.5 ml. min-1. kg-1; P < 0.05). Conclusions A subparalyzing dose of pancuronium decreased plasma cholinesterase activity and the clearance of the two most active isomers of mivacurium. Pancuronium potentiates mivacurium more than other neuromuscular blocking agents because, in addition to its occupancy of postsynaptic acetylcholine receptors, it slows down the hydrolysis of mivacurium.

Acceleration of Plasma Cholinesterase Activity by Quaternary Ammonium Salts

Science ◽  
1958 ◽  
Vol 128 (3315) ◽  
pp. 92-93 ◽  
Author(s):  
E. G. ERDOS ◽  
F. F. FOLDES ◽  
E. K. ZSIGMOND ◽  
N. BAART ◽  
J. A. ZWARTZ
Keyword(s):  
Quaternary Ammonium ◽  
Cholinesterase Activity ◽  
Plasma Cholinesterase ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Plasma Cholinesterase Activity

Management of Methomyl Poisoning

1990 ◽  
Vol 9 (4) ◽  
pp. 251-254 ◽  
Author(s):  
J. Martinez-Chuecos ◽  
F. Molinero-Somolinos ◽  
J. Solé-Violàn ◽  
R. Rubio-Sanz
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Total Dose ◽  
Activated Charcoal ◽  
Cholinesterase Activity ◽  
Gastric Lavage ◽  
Plasma Cholinesterase ◽  
Acute Stage ◽  
Plasma Cholinesterase Activity ◽  
Small Doses

Eleven patients who suffered methomyl poisoning were admitted to the intensive care unit. All of them showed cholinergic symptoms similar to that produced by organophosphate insecticides but of lesser intensity. Plasma cholinesterase activity was normal in four patients and moderately lower in the remainder (always above 32%). All of the patients showed miosis and none presented with bradycardia. No complications were detected in the acute stage or on further examination a month later. The treatment applied was: (1) gastric lavage or washing the skin; (2) the administration of activated charcoal; (3) small doses of atropine according to symptoms (average of total dose 4.3 mg). All of the patients recovered within 24-48 h. In conclusion, we can assume that methomyl poisoning does not produce serious complications if moderate surveillance is assumed. Only small doses of atropine are required to counteract symptoms.

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