Decrease In Cholinesterase Activity Research Articles

Relationship between behavioral changes and brain cholinesterase activity following graded intracerebral injections of DFP.

The relationship between the amount of DFP injected into the right caudate nucleus and the resulting decreased chol-inesterase activity has been investigated in regard to the appearance of forced circus movements. DFP in doses of less than 0.01 mg had no observable behavioral effect and did not lower the ChE activity to 40% of the control value. Doses of from 0.01 to 0.16-mg, however, caused persistent contraversive forced circling and decreased the cholines-terase value of the nucleus caudatus to from 21 to 40% of normal. There was no evidence of significant spread of the DFP within the brain in this group of animals. The administration of atropine sulfate either prevents or stopped these forced circus movements. Persistent forced circling could also be induced with larger doses of from 0.23 to 0.32 mg of DFP and evidence of spread of the DFP was then observed. In this group the injected nucleus caudatus showed ChE activity values of from 18 to 20% of the control whereas remaining parts of the brain revealed symmetrical reduction in ChE activity between 48 to 82% of normal. When still greater amounts of DFP were injected (1 to 10 mg) the spread of this substance progressively increased so that eventually ChE activity was decreased bilaterally and transient circling or death resulted.

Cation transport in erythrocytes treated with lecithinase A

1. 1. Treatment of human blood with lyophilized snake venom (1 μg./ ml.) containing lecithinase resulted in removal of 50–60% of the cholinesterase from the erythrocyte. 2. 2. The glycolytic activity of erythrocytes was unchanged by this treatment. 3. 3. The active transport of K into and Na out of erythrocytes was impaired in venom-treated cells. This impairment is not correlated with any defect in glycolytic activity but may be correlated with a decreased cholinesterase activity.

Decreased cholinesterase activity of rat kidney following adrenalectomy and its reactivation in vitro by certain steroids.

ArticleDecreased Cholinesterase Activity of Rat Kidney Following Adrenalectomy and Its Reactivation in Vitro by Certain SteroidsMargaret E. Greig, and M. Kathleen CarterMargaret E. GreigFrom the Department of Pharmacology, Upjohn Company, Kalamazoo, Michigan and the Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, and M. Kathleen CarterFrom the Department of Pharmacology, Upjohn Company, Kalamazoo, Michigan and the Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TennesseePublished Online:01 Sep 1954https://doi.org/10.1152/ajplegacy.1954.178.3.433MoreSectionsPDF (658 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByEffects of hypophysectomy on acetylcholinesterase and butyrylcholinesterase in the ratBiochemical Pharmacology, Vol. 32, No. 7Cholinesterase in der ChirurgieHormoneThe Distribution of Cholinesterases in Cats and Changes Caused by Hypophysectomy, Adrenalectomy, Undernutrition and DOCA.Acta Physiologica Scandinavica, Vol. 37, No. 2-3 More from this issue > Volume 178Issue 3September 1954Pages 433-436 Copyright & PermissionsCopyright © 1954 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1954.178.3.433PubMed13207351History Received 26 April 1954 Published online 1 September 1954 Published in print 1 September 1954 Metrics

The relation of the choline cycle to cardiac decompensation: Acetylcholine metabolism in the dog heart-lung preparation

1. 1. The cholinesterase occurring in dog heart muscle is predominantly of the nonspecific type. 2. 2. Pentobarbital failure is often accompanied by a decreased cholinesterase activity in the heart muscle. 3. 3. Ouabain administration to the heart decompensated by pentobarbital results in a maintenance of or an increase in cholinesterase activity concomitantly with its positive inotropic effect. 4. 4. Decompensation can be produced by large doses of penicillin G, physostigmine, or diisopropyl fluorophosphate, agents known to be inhibitory in the choline cycle. Failure by penicillin G is poorly remediable by ouabain. Ouabain is effective to a variable degree in physostigmine and diisopropyl fluorophosphate failure. 5. 5. Choline in large doses is positively inotropic in the atropinized dog heart-lung preparation failed by any of these compounds. Its administration hinders subsequent failure by physostigmine or pentobarbital, and results in a partial relief of physostigmine inhibition of cholinesterase. 6. 6. Benzoylcholine has positive inotropic activity in failure produced by penicillin G and impedes decompensation by physostigmine. Benzoylcholine inhibits the positive inotropic effect of choline. 7. 7. Ouabain may function to relieve esterase inhibition or (less likely) to release acetylcholine from its protein complex. 8. 8. The hypothesis is offered that these types of decompensation are the result of interference with the choline cycle as it pertains to cell membrane integrity, and that other types of decompensation may have a similar etiology.

Effect of trimethadione (tridione) and other drugs on convulsions caused by di-isopropyl fluorophosphate (DFP).

Trimethadione in doses of 200-400 mg/kg restores the normal electroencephalogram after the production of grand-mal-like electrical patterns in rabbits by DFP. Trimethadione when administered before DFP prevents the establishment of the seizure pattern, though not of milder types of excessive activity. A profound fall of cholinesterase activity is observed, and presumably acetylcholine accumulates. Despite its valuable therapeutic effects trimethadione does not hinder the extreme decrease of cholinesterase activity. Atropine, like trimethadione, both prevents the electrical seizures and restores the control electroencephalogram after the abnormal brain waves have been evoked by DFP, and yet the cholinesterase activity is also greatly diminished and to the same extent as it is in the absence of atropine. Pentothal has been used successfully to restore the normal electroencephalogram after seizure patterns have been produced. Phenobarbital possesses both preventive and curative effects while dilantin has bee...

Effects of di-isopropyl fluorophosphate (DFP) on electroencephalogram and cholinesterase activity

1. 1. The intracarotid injection of DFP produces electrical changes in the corticogram of the unanesthetized rabbit which, within limits, are proportionate to the amounts of the anticholinesterase administered. 2. 2. The decrease of cholinesterase activity in various parts of the brain is correlated with the degree of the abnormality produced in the electrocorticogram. This relationship fails however when the grand mal-like electrical patterns develop as the cholinesterase activity has previously fallen to a minimum. 3. 3. It is suggested that in the production of the grand mal-like electrical pattern multiple factors may be involved.

Mechanism of Drug Addiction and Drug Tolerance

IT has been found that prolonged administration of ‘luminal’ (and other barbiturates) to human beings (for example, epileptics) and animals greatly reduces the cholinesterase activity of the serum, so that it reaches 10–20 per cent of what it was before the treatment with the drug. No change in cholinesterase activity was found, however, when the drug was added to serum in vitro (2.5 mgm./c.c.). It appears that the barbiturate does not act directly on the enzyme asin the case of eserine and other anticholinesterase substances. The pronounced decrease in cholinesterase activity which was found in vivo might be interpreted as a counter-adaptation, the activity of the cholinergic system being reduced by the narcotic, reducing thereby the demand for cholinesterase, which, consequently, slowly decreases.