Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030567 (Parkinson's disease)
 63,064 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The anticholinergic drug orphenadrine is used in the treatment of Parkinson's disease. In this study we evaluate the neuroprotective effects of orphenadrine on excitotoxicity in vivo and in vitro. Orphenadrine prevented the mitochondrial and the cytoplasmic membrane potential decrease evoked by NMDA (100 microM) in rat dissociated cerebellar granule cells showing an IC50 value of 11.6 +/- 4.7 microM (mean +/- SEM, n = 5) and 13.5 +/- 2.3 microM (n = 3), respectively. Orphenadrine was able to protect cerebellar granule cell cultures from glutamate-induced neurotoxicity. Kainic acid (KA, 10 mg/kg)-induced excitotoxicity was evaluated in vivo using the microglial marker peripheral-type benzodiazepine receptor (PBR) and heat shock protein 72 (HSP72) expression in the hippocampus. The Bmax of PBR for control tissues was 589.1 +/- 40.0 fmol/mg protein (n = 4), increasing to 1692.5 +/- 51.6 fmol/mg protein (n = 5) after the KA treatment. Pretreatment with orphenadrine (10 mg/kg) blocked the KA-induced increase in PBR density. As expected, KA-administration induced the expression of HSP72 that was blocked in the orphenadrine + KA-treated rats. We demonstrate that orphenadrine, interacting at the NMDA receptor, is able to prevent the neurotoxicity mediated by activation at glutamate ionotropic receptors.
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PMID:In vitro and in vivo protective effect of orphenadrine on glutamate neurotoxicity. 1034 Mar 4

Orphenadrine is an anticholinergic drug used mainly in the treatment of Parkinson's disease. It has a peripheral and central effect and a known cardiotoxic effect when taken in large doses. We report the successful outcome of the treatment of a 2 1/2-year-old girl who accidentally ingested 400 mg of orphenadrine hydrochloride (Disipal). One hour after ingestion she presented neurological symptoms: confusion, ataxic walking, and periods of severe agitation. Generalized tonic-clonic seizures appeared resistant to the administration of multiple antiepileptics. They ceased after a supplementary dose of intravenous diazepam, endotracheal intubation, and mechanical ventilation. An episode of ventricular tachycardia responded well to i. v. lidocaine. Physostigmine was administered in three successive doses. The initial orphenadrine plasma level (3,55 microg/ml) was in the toxic range, associated with high mortality. The calculated elimination half-life was 10.2 h and the molecule and/or its metabolites were found up to 90 h after ingestion.
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PMID:Orphenadrine poisoning in a child: clinical and analytical data. 1055 71

Orphenadrine is a drug acting on multiple targets, including muscarinic, histaminic, and NMDA receptors. It is used in the treatment of Parkinson's disease and in musculoskeletal disorders. It is also used as an analgesic, although its mechanism of action is still unknown. Both physiological and pharmacological results have demonstrated a critical role for voltage-gated sodium channels in many types of chronic pain syndromes. We tested the hypothesis that orphenadrine may block voltage-gated sodium channels. By using patch-clamp experiments, we evaluated the effects of the drug on whole-cell sodium currents in HEK293 cells expressing the skeletal muscle (Nav1.4), cardiac (Nav1.5) and neuronal (Nav1.1 and Nav1.7) subtypes of human sodium channels, as well as on whole-cell tetrodotoxin (TTX)-resistant sodium currents likely conducted by Nav1.8 and Nav1.9 channel subtypes in primary culture of rat DRG sensory neurons. The results indicate that orphenadrine inhibits sodium channels in a concentration-, voltage- and frequency-dependent manner. By using site-directed mutagenesis, we further show that orphenadrine binds to the same receptor as the local anesthetics. Orphenadrine affinities for resting and inactivated sodium channels were higher compared to those of known sodium channels blockers, such as mexiletine and flecainide. Low, clinically relevant orphenadrine concentration produces a significant block of Nav1.7, Nav1.8, and Nav1.9 channels, which are critical for experiencing pain sensations, indicating a role for sodium channel blockade in the clinical efficacy of orphenadrine as analgesic compound. On the other hand, block of Nav1.1 and Nav1.5 may contribute to the proconvulsive and proarrhythmic adverse reactions, especially observed during overdose.
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PMID:Involvement of voltage-gated sodium channels blockade in the analgesic effects of orphenadrine. 1921 9

Orphenadrine is an anticholinergic drug used in the treatment of Parkinson's disease, and is also known to exert nonspecific antagonistic activity at the phencyclidine binding site of the N-methyl-D-aspartate (NMDA) receptor. The aim of this study was to assess the anticonvulsant properties of orphenadrine and to evaluate its effect on the anticonvulsant activity of antiepileptic drugs against maximal electroshock-induced seizures in mice. Orphenadrine given at a dose of 5.65 mg/kg elevated the electrical seizure threshold from 5.7 (5.4-6.1) to 6.8 (6.3-7.3) mA, while a dose of 2.8 mg/kg was ineffective. The ED(50) values of orphenadrine administered 10, 30 and 120 min before maximal electroshock-induced convulsions were 16.8 (11.3-25.1), 17.8 (15.7-20.0) and 25.6 (23.3-28.3) mg/kg, respectively. Orphenadrine at a sub-threshold dose of 2.8 mg/kg significantly enhanced the anticonvulsant activity of valproate by reducing its ED(50) value from 315.8 (270.0-369.4) to 245.9 (207.1-292.0) mg/kg without affecting the free plasma levels of valproate. However, orphenadrine failed to enhance the protective activity of carbamazepine, phenytoin, phenobarbital, lamotrigine, topiramate, or oxcarbazepine against maximal electroshock-induced seizures.
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PMID:Influence of orphenadrine upon the protective activity of various antiepileptics in the maximal electroshock-induced convulsions in mice. 1981 57