Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Current treatment of nerve agent poisoning consists of prophylactic administration of pyridostigmine and therapy using atropine, an oxime and a benzodiazepine. Pyridostigmine does however not readily penetrate the blood-brain barrier giving ineffective protection of the brain against centrally mediated seizure activity. In this study, we have evaluated donepezil hydrochloride, a partial reversible inhibitor of acetylcholinesterase (AChE) clinically used for treating Alzheimer's disease, in combination with procyclidine, used in treatment of Parkinson's disease and schizophrenia, as prophylaxis against intoxication by the nerve agent soman. The results demonstrated significant protective efficacy of donepezil (2.5 mg/kg) combined with procyclidine (3 or 6 mg/kg) when given prophylactically against a lethal dose of soman (1.6 x LD(50)) in Wistar rats. No neuropathological changes were found in rats treated with this combination 48 h after soman intoxication. Six hours after soman exposure cerebral AChE activity and acetylcholine (ACh) concentration was 5% and 188% of control, respectively. The ACh concentration had returned to basal levels 24 h after soman intoxication, while AChE activity had recovered to 20% of control. Loss of functioning muscarinic ACh receptors (17%) but not nicotinic receptors was evident at this time point. The recovery in brain AChE activity seen in our study may be due to the reversible binding of donepezil to the enzyme. Donepezil is well tolerated in humans, and a combination of donepezil and procyclidine may prove useful as an alternative to the currently used prophylaxis against nerve agent intoxication.
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PMID:The combination of donepezil and procyclidine protects against soman-induced seizures in rats. 1728 99

Reversible acetylcholinesterase inhibitor donepezil displays prophylactic effects against intoxication with irreversible organophosphorous acetylcholinesterase inhibitors. We used behavioural observation of yawning and epileptic seizures, histochemical acetylcholinesterase staining, and in situ hybridization of the immediate early genes, c-fos and synaptotagmin 4 (Syt4) mRNAs in the brain, to evaluate whether donepezil could protect the brain against the effects of the organophosphate anticholinesterase, diisopropylfluorophosphate, in a rat model of intoxication. Diisopropylfluorophosphatetreated animals exhibited frequent yawning, significant inhibition of acetylcholinesterase staining and upregulation of c-fos mRNA, but not the epileptic seizures or significant change of Syt4 mRNA levels. In order to reduce the threshold for the induction of cholinergic seizures, additional groups of rats were pre-treated with LiCl 24 h before the treatment with diisopropylfluorophosphate. These rats exhibited the seizures, a significant inhibition of acetylcholinesterase staining and significant upregulation of c-fos and Syt4 mRNA levels. All the above-mentioned effects of diisopropylfluorophosphate were inhibited by donepezil pre-treatment. Donepezil pre-treatment by itself induced only a comparatively weaker inhibition of acetylcholinesterase staining and infrequent yawning. We conclude that donepezil protects the brain against diisopropylfluorophosphate-induced effects and that Syt4 mRNA upregulation may serve as a novel marker for organophosphate-induced seizures.
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PMID:Donepezil inhibits diisopropylfluorophosphate-induced seizures and up-regulation of synaptotagmin 4 mRNA. 2132 67

Epileptic seizures are short episodes of abnormal brain electrical activity. Many survivors of severe epilepsy display delayed neuronal death and permanent cognitive impairment. Donepezil is an acetylcholinesterase inhibitor and is an effective treatment agent for Alzheimer's disease. However, the role of donepezil in seizure-induced hippocampal injury remains untested. Temporal lobe epilepsy (TLE) was induced by intraperitoneal injection of pilocarpine (25 mg/kg). Donepezil (2.5 mg/kg/day) was administered by gavage in three different settings: (1) pretreatment for three days before the seizure; (2) for one week immediately after the seizure; and (3) for three weeks from three weeks after the seizure. We found that donepezil showed mixed effects on seizure-induced brain injury, which were dependent on the treatment schedule. Pretreatment with donepezil aggravated neuronal death, oxidative injury, and microglia activation. Early treatment with donepezil for one week showed neither adverse nor beneficial effects; however, a treatment duration of three weeks starting three weeks after the seizure showed a significant reduction in neuronal death, oxidative injury, and microglia activation. In conclusion, donepezil has therapeutic effects when injected for three weeks after seizure activity subsides. Therefore, the present study suggests that the therapeutic use of donepezil for epilepsy patients requires a well-conceived strategy for administration.
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PMID:Diverse Effects of an Acetylcholinesterase Inhibitor, Donepezil, on Hippocampal Neuronal Death after Pilocarpine-Induced Seizure. 2909 58