Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We used saturation radioligand binding to measure nine types of serotonin receptors in 13 neuroblastomas from children. 5-HT1E and 5-HT3 sites were found in neuroblastomas with receptor density and affinity similar to human or rat brain. No 5-HT1A, 5-HT1B, 5-HT1C, 5-HT1D, 5-HT2, or 5-HT uptake sites were found in any of the tumors, although all were detected in human or rat brain. These data demonstrate that human neuroblastomas possess 5-HT receptors found in human brain and relevant to human myoclonus. We speculate that 5-HT receptors in human neural crest-derived tumors may have clinical and neurobiological significance.
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PMID:Serotonin receptors in human neuroblastoma: a possible biologic tumor marker. 153 97

We have previously reported the presence of posthypoxic, audiogenic myoclonus in rats after cardiac arrest and the ability of the 5-HT precursor, 5-HTP, to attenuate these muscle jerks. In addition, we have recently shown that 5-HT2 and 5-HT3 agonists can reduce the severity of myoclonus in these animals, suggesting a deficiency in serotonergic neurotransmission. In the present study, the levels of 5-HTP, 5-HT, and 5-HIAA were measured in seven regions of the brain in myoclonic and normal rats to identify the areas of the brain in which a serotonergic dysfunction resides. Similar to previous studies, we observed pronounced posthypoxic, audiogenic myoclonus 3 and 14 days after resuscitation from cardiac arrest, with a resolution of the abnormal movements by 45 days postarrest. HPLC measurements revealed significant changes in indole levels in the following areas of the brain: cortical 5-HIAA, striatal 5-HT, striatal 5-HIAA, hippocampal 5-HT, mesencephalic 5-HIAA, myelencephalic 5-HT, myelencephalic 5-HIAA, cerebellar 5-HTP, and cerebellar 5-HT. The changes in striatal 5-HT, cortical 5-HIAA, and mesencephalic 5-HIAA appear most relevant to the pathophysiology of posthypoxic myoclonus because regression analyses showed significant correlations between the myoclonus scores of the animals and the levels of these indoles. Based on the observed pattern of results, we postulate a dysfunction in serotonergic lateral (cortical) and far lateral (extrapyramidal) ascending pathways in posthypoxic myoclonus.
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PMID:Association between brain indole levels and severity of posthypoxic myoclonus in rats. 754 90

Male Sprague-Dawley rats underwent cardiac arrest and resuscitation, subsequently exhibiting posthypoxic myoclonus. The audiogenic posthypoxic myoclonus in these animals could be attenuated with the following drugs: 5-hydroxytryptophan (5-HTP, serotonin [5-HT] precursor), N-(3-trifluoro-methylphenyl)piperazine hydrochloride (TFMPP, 5-HT1B/1C/2 agonist), (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrobromide (DOI, 5-HT2 agonist), and 1-(m-chlorophenyl)-biguanide hydrochloride (m-CPBG, 5-HT3 agonist). In contrast, the following drugs were ineffective: (+/-)-8-hydroxy-dipropylaminotetralin hydrobromide (8-OH-DPAT, 5-HT1A agonist), buspirone hydrochloride (5-HT1A agonist), 7-trifluoromethyl-4(4-methyl-l-piperazinyl)-pyrrolo[1,2- a]quinoxaline maleate (CGS 12066B, 5-HT1B agonist), ketanserin tartrate (5-HT2 antagonist), methysergide maleate (5-HT2 antagonist), fluoxetine (5-HT uptake blocker), and saline (vehicle). The data suggest that enhancement of serotonergic activity, particularly through 5-HT2 and 5-HT3 receptors, have therapeutic potential for the treatment of posthypoxic myoclonus.
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PMID:Effects of selective serotonergic ligands on posthypoxic audiogenic myoclonus. 855 14

In guinea pigs, myoclonus can be induced by 5-hydroxytryptamine (5-HT, serotonin) precursors and synthetic 5-HT receptor agonists, yet the receptor subtype specificity of this behavior is not fully delineated. Guinea pigs were pre-treated with carbidopa (50 mg) followed by one of eight 5-HT antagonists: (-)-N-tert-butyl-3-[4-(2-methoxyphenyl) piperazin-1-yl]-2-phenyl propionamide ((-)-WAY 100135) (5-HT1A), N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]-ethyl]-N-(2-pyridyl)-cy clohexancarboxamide (WAY 100635) (5-HT1A), methiothepin mesylate (5-HT1/2), mesulergine hydrochloride (5-HT2A/2C), N[4-methoxy-3-(4-methyl-L-piperazinyl)phenyl]-2'-methyl-4'-(5-methyl-1,2 ,4-oxadizol-3-yl) (GR 127935) (5-HT1D), trans-4-[(3Z)3-(2-dimethylaminoethyl)oxyimino-3(2-fluorop hen yl) propen-1-yl]phenol, hemifumarate (SR 46349) (5-HT2), ondansetron hydrochloride (5-HT3), and [1-[2-[methylsulphonyl)amino]ethyl]-4-piperidinyl]methyl-5-fluoro-2-meth oxy-1H-indole-3-carboxylate (GR 125487) (5-HT4). Thirty minutes later, they received 5-hydroxytryptophan (5-HTP) (75 mg/kg, sc) and myoclonic jumping rates were assessed every 10 min for 200 min by a blinded observer. Repeated measures analysis of variance of drug-induced antagonism of 5-HTP-induced myoclonus revealed a significant effect for the 5-HT receptor antagonists methiothepin mesylate, GR127935, and mesulergine hydrochloride compared to placebo, and each of these drugs inhibited 5-HTP-induced myoclonus in a dose-dependent fashion. Based on the receptor profiles of the three effective antagonists, 5-HTP-induced myoclonus is influenced by the 5-HT1/2 receptor systems. The absence of a significant change with any other receptor subtype antagonist suggests that myoclonus is not related to diffuse activation of central serotonergic mechanisms.
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PMID:5-Hydroxytryptophan-induced myoclonus in guinea pigs: mediation through 5-HT1/2 receptor subtypes. 965 Aug 47