Received: Revised: Accepted: April 13, 2013 April 17, 2013 April 24, 2013 In the present report, a new assay combining specific substrates and a selective BChE inhibitor (ethopropazine hydrochloride) was used to measure both AChE and BChE in canine whole blood samples. Acetylthiocholine iodide (ATCI) and butyrylthiocholine iodide (BTCI) were used as substrates, whereas 2,2’dithiodipiridine was ...

A simplified manual and automated method is described for measuring serum cholinesterase activity and identifying the homozygous “usual,” heterozygous, and homozygous “atypical” forms of the enzyme. With butyrylthiocholine as substrate at pH 7.4, the activity is determined in two 0.05 mol/liter buffer systems, Tris and phosphate. The “usual” enzyme has the same activity in both buffer systems. ...

Organophosphorous compounds have been employed as pesticides and chemical warfare nerve agents. Toxicity of organophosphorous compounds is a result of excessive cholinergic stimulation through inhibition of acetyl cholinesterase. Clinical manifestations include cholinergic syndromes, central nervous system and cardiovascular disorders. Organophosphorous pesticide poisonings are common in develo...

Background: Tert-butyl mercaptan is one of the frequently used odorants derived from natural gases. It has been declared as a health hazard by the Occupational Safety and Health Administration (OSHA) in the USA. There is not much information available about the mercaptans long-term toxicity secondary to occupational exposure. This study was conducted to evaluate the oxidative stress caused by m...

Previous communications from this Laboratory have shown that the inhibition of cy-chymotrypsin by diisopropyl fluorophosphate (DFP) is a stoichiometric reaction that comprises the introduction of a single diisopropyl phosphate group into the molecule of cu-chymotrypsin, the elimination of fluorine as HF, and the production of an undenatured, crystallizable, inhibited enzyme protein (l-3). Sever...

OBJECTIVE To determine whether (i) cholinesterase activity is increased in the saliva of patients with primary Sjogren's syndrome (pSS), (ii) increased levels of cholinesterase of lymphocyte origin could interfere with the secretory activity of submandibular acinar cells, and (iii) hydroxychloroquine at therapeutic doses could interfere with cholinesterase activity. METHODS The Ellman method ...

The inhibitory effect of (+/-) propranolol 1.69 x 10(-4)-1.69 x 10(-7) mol litre-1 on normal and atypical plasma cholinesterase variants was investigated. The atypical enzyme is less sensitive to inhibition by (+/-) propranolol or either of its enantiomorphs than the usual enzyme. Propranolol 8.45 x 10(-6) mol litre-1 was used as differential inhibitor of 643 plasma samples from individuals of ...

In this study, a commercially available kit in which propionylthiocholine is used as a substrate and a dibucaine solution to determine the variants of the enzyme were utilized. Plasma cholinesterase activity of 151 patients who underwent different operations was measured during a period of six months. The mean±SD of the enzyme activity in 150 patients was 4.39±1.17 kU/L .. Seventeen patie...

Sir,—The work of Professor James and others in South Africa on nitrous oxide at high altitudes is of course well known; any review on awareness would certainly include it. Excluding this work (and some otheT important topics) from my article was solely a result of lack of space; an Editorial cannot be a complete review. Our objective is usually to select areas which are controversial, poorly un...