Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sarin is a highly toxic organophosphonate and neural enzyme acetylcholinesterase (AChE) inhibitor. Inhibition of AChE causes large accumulation of acetylcholine at synaptic cleft leading to hyper activation of nicotinic and muscarinic acetylcholine receptors, causing excessive secretions, muscle fasciculation, nausea, vomiting, respiratory distress and neurological effects. There are cases in which long term psychomotor function deficiency, reduced learning and memory functions have been observed several years after exposure of sarin among survivors. This phenomenon is called Organophosphorus ester Induced Chronic Neurotoxicity (OPICN) and cannot be explained by AChE inhibition alone. Plasma proteomics at earlier stages was carried out to study changes reflected at blood level that can help predict possible neurological insults at an early time point to take proper therapeutic interventions against OPICN. In the present study, a 0.5 LD50 dose of sarin was administered to Wistar rats and possible changes in blood plasma proteomic profile were investigated after one and seven days of sarin exposure. Proteins were separated on 2-dimensional gel electrophoresis and identified by MALDI-TOF/MS. Expression profile of major proteins was validated by Western blot. Result showed that after exposure of sarin inhibition of AChE persisted after one week of exposure. There were 14 plasma proteins that showed significant changes in expression (>1.5-fold). It included proteins related to immune function, neurodegenerative condition and chaperone function. Interestingly sarin exposure caused decreased expression of plasma Apolipoprotein A-1 and Haptoglobin on day seven, which are the putative early molecular markers for cognitive impairment and neurodegenerative changes.
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PMID:Increased expression of immune modulator proteins and decreased expression of apolipoprotein A-1 and haptoglobin in blood plasma of sarin exposed rats. 2677 79

Since the development in the 1950's of 2-PAM (Pralidoxime), an antidote that reactivates organophosphate conjugated acetylcholinesterase in target tissues upon pesticide or nerve agent exposure, improvements in antidotal therapy have largely involved congeneric pyridinium aldoximes. Despite seminal advances in detailing the structures of the cholinesterases as the primary target site, progress with small molecule antidotes has yet to define a superior agent. Two major limitations are immediately apparent. The first is the impacted space within the active center gorge, particularly when the active center serine at its base is conjugated with an organophosphate. The reactivating nucleophile will have to negotiate the tortuous gorge terrain to access the phosphorus atom with its most nucleophilic form or ionization state, the oximate anion. A second limitation stems from the antidote crossing the blood-brain barrier sufficiently rapidly, since it is well documented that central acetylcholinesterase inhibition gives rise to cardiovascular and respiratory compromise. The associated hypoxia then leads to a sequelae of events, including poor perfusion of the brain and periphery, along with muscle fasciculation, tremors and eventually seizures. We consider both the barriers confronting and further achievements necessary to enhance efficacy of antidotes.
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PMID:Assessment of ionizable, zwitterionic oximes as reactivating antidotal agents for organophosphate exposure. 3110 Feb 77

Myofascial trigger points (MTrPs) are defined as hyperirritable spots in a palpable taut band (TB) of skeletal muscle fibers. Knowing the formation and location of MTrPs is a great help to prevent their development and inactivate existing MTrPs. This study aimed to obtain new evidence that myofascial trigger spots (MTrSs), which are similar to human MTrPs, are found in dysfunctional motor endplates by observing the morphological characteristics of muscles and changes in biochemical substances. A total of 32 male Sprague Dawley rats were randomly divided into four groups: two control groups (i.e., C1 and C2) and two model groups (i.e., M1 and M2). C1 and M1 were used for acetylcholine (ACh) content measurement, while C2 and M2 were utilized for acetylcholinesterase (AChE) staining. In the model groups, blunt striking injury was induced and eccentric exercise was applied to the left gastrocnemius for 8 weeks. After 1 month, spontaneous electrical activity(SEA), AChE optical density (OD), muscle fiber diameter, and ACh content were measured. The results showed that extensive abnormal endplate noise (aEPN), including positive neurons, fibrillation potentials, fasciculation potential, and high amplitude (endplate spikes [EPS]), is present at MTrSs in M1. Quantitative electromyography results showed that the amplitudes of aEPN and frequency of EPS in M1 were significantly higher than those of C1. The ACh content of MTrSs in M1 was significantly higher than that in C1. The AChE OD value of M2 was significantly lower than that of C2. In addition, the diameter of the muscle fibers in the AChE-stained area was longer in M2 than in C2. In conclusion, MTrSs formed at the motor endplate with a larger diameter of muscle fibers. Excessive ACh release and decreased AChE activity at MTrSs stimulated muscle action potential and muscle contraction.
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PMID:Structural and functional abnormalities of motor endplates in rat skeletal model of myofascial trigger spots. 3139 57


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