Human Cholinesterase Research Articles

Effects of psychotropic compounds on enzyme systems. I. Inhibition of human plasma and erythrocyte cholinesterases.

SummaryInhibition constants for 5 phenothiazines, chlorpromazine, promazine, secergan, thiopropazate and triflupromazine, using the systems human erythrocyte acetylcholinesterase with acetyl-β-methylcholine chloride as substrate and human plasma cholinesterase with both acetylcholine and butyrylcholine as substrates were determined. The mechanism of inhibition was of the mixed type for acetylcholinesterase, and of the competitive or partially competitive type for plasma cholinesterase. In vitro inhibition appeared to be unrelated to activity in the case of acetylcholine esterase and inversely related in the case of plasma cholinesterase.

308 The influence of chemical structure on the interaction of gamma-aminobutyrylcholine derivatives and human cholinesterases

308 The influence of chemical structure on the interaction of gamma-aminobutyrylcholine derivatives and human cholinesterases

The Inhibition of Human Plasma Cholinesterase by Sevin, Parathion, Phosdrin, Trithion, and Systox: A Comparison of Ten Enzyme Samples, and Use of Sevin as Standard

The Inhibition of Human Plasma Cholinesterase by Sevin, Parathion, Phosdrin, Trithion, and Systox: A Comparison of Ten Enzyme Samples, and Use of Sevin as Standard

PROTECTION OF HUMAN RED CELL CHOLINESTERASE AGAINST INHIBITION BY TABUN AND O,O-DIETHYL-S-2-DIETHYLAMINOETHYL PHOSPHOROTHIOLATE

PROTECTION OF HUMAN RED CELL CHOLINESTERASE AGAINST INHIBITION BY TABUN AND O,O-DIETHYL-S-2-DIETHYLAMINOETHYL PHOSPHOROTHIOLATE

The effect of several psychotomimetic drugs on human serum cholinesterase.

The effects of a number of drugs of psychiatric interest on human serum cholinesterase are reported. The reported occurrence of an atypical form of human serum cholinesterase, differing in sensitivity to some inhibitors, has been confirmed. LSD and BOL, both potent inhibitors of human serum cholinesterase, do not fit into any of the three groups of inhibitors defined by their relative effectiveness as inhibitors of typical and atypical human serum cholinesterase. Some of the limitations of these findings are discussed.

Cholinesterase activity and potassium permeability in human erythrocytes.

SummaryInhibition of human erythrocyte cholinesterase with or without exogenous AcCh had no effect on loss of potassium from cells during storage at 4°C or during incubation at 37.5°C. The re-entry at 37.5°G of potassium into cells previously stored for 24 hours at 4°C to permit its leakage into the serum was also unaffected.

Use of oximes in the treatment of intoxication by anticholinesterase compounds in normal subjects

The oximes, pyridine-2-aldoxime (2-PAM) and diacetyl monoxime (DAM), protected against the inhibition of human cholinesterase enzymes by organophosphorus and quaternary ammonium anticholinesterase compounds in vitro, and 2-PAM reversed this inhibition. The oximes reversed neuromuscular block and plasma and red blood cell cholinesterase inhibition produced in normal subjects by the administration of sarin, neostigmine, bis-neostigmine, pyridostigmine, bis-pyridostigmine and ambenomium. The intravenous dose required to alleviate generalized weakness was 1,000 to 2,000 mg. These doses did not relieve the muscarine-like effects of the anticholinesterase compounds, and their influence on central neural effects was not pronounced. DAM produced local burning and mild systemic symptoms. 2-PAM produced a transient, local neuromuscular block following the intra-arterial injection of high concentrations. This was enhanced by the prior injection of anticholinesterase compound. 2-PAM and DAM are valuable adjuncts to atropine in the management of anticholinesterase intoxication, and should diminish the necessity for, or duration of, artificial respiration and endotracheal intubation.

Interrelationship of murexine, dihydromurexine and human cholinesterases.

Summary1. Murexine (Mur) and dihydromurexine (DhMur) are both hydrolyzed by human plasma cholinesterase. The hydrolysis rate of DhMur is as fast as that of acetylcholine (ACh) and is 18 times faster than that of Mur. 2. Neither Mur nor DhMur are hydrolyzed by human red cell cholinesterase. 3. Both Mur and DhMur inhibit the hydrolysis of ACh by red cell cholinesterase. Mur also inhibits plasma cholinesterase.

The Inhibitory Effect of Neuromuscular Blocking Agents and Their Antagonists on Human Cholinesterases

The Inhibitory Effect of Neuromuscular Blocking Agents and Their Antagonists on Human Cholinesterases

Relative effectiveness of certain drugs against shock produced in mice from tourniquet and burn trauma.

The therapeutic effectiveness of chlorpromazine, dibenamine, l-norepinephrine, 1-ethylsulfonyl-4-ethyl-piperazine hydrochloride, serotonin, ascorbic acid, human plasma cholinesterase and a bacterial polysaccharide (Piromen), has been studied in experimental tourniquet and burn shock in mice. Employing survival as an indication of therapeutic effect, simultaneous comparisons were made of the survival of groups of animals receiving these agents in saline and control groups receiving saline alone. Chlorpromazine pretreatment (8–20 mg/kg) produced reproducible positive effects on survival whether given alone or in conjunction with saline replacement therapy. Dibenamine pretreatment (5–25 mg/kg) produced positive effects on survival but this response was not always reproducible. No beneficial effect was demonstrable following administration of the remainder of these agents when compared to control groups given saline alone.

THE INHIBITION OF PURIFIED, HUMAN PLASMA CHOLINESTERASE WITH DIISOPROPYL FLUOROPHOSPHATE

THE INHIBITION OF PURIFIED, HUMAN PLASMA CHOLINESTERASE WITH DIISOPROPYL FLUOROPHOSPHATE

A study of cholinesterase activity in the blood of normal subjects.

Abstract Our results confirm the findings of previous workers that in the human subject cholinesterase activity of the red blood cell is greater than that of the plasma. The cholinesterase activity may vary widely from individual to individual, but tends to remain fairly constant in any one individual.