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)

Post-hypoxic intention myoclonus successfully treated by long-term administration of the combination of 5-hydroxytryptophan and carbidopa is described. Persistent euphoria and diarrhoea were essential side effects. Methysergide (12 mg/day) blocked the therapeutic effect, indicating a specific serotoninergic function of precursor loading with 5-hydroxytryptophan. Tryptophan (8 g/day) had no effect on the myoclonus suggesting a reduced tryptophan hydroxylase activity. Plasma concentrations of 5-hydroxytryptophan in the range of 10--30 micromoles per liter were obtained during maintenance therapy with 900 mg 5-hydroxytryptophan per day in combination with 150 mg carbidopa per day.
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PMID:Post-hypoxic intention myoclonus treated with 5-hydroxy-tryptophan and an extracerebral decarboxylase inhibitor. 30 27

Tryptamine (1-320 mg/kg) evoked only slight muscle jerking in naive guinea-pigs but, in animals pretreated with pargyline (75 mg/kg; 1 hr previously), tryptamine induced a dose-dependent (6-160 mg/kg) myoclonus. The myoclonus induced by tryptamine (40 mg/kg) plus pargyline (75 mg/kg) was differentially inhibited by the indoleamine receptor antagonists, methergoline (5 mg/kg) which was more potent than methysergide (10 mg/kg), mianserin (10 mg/kg) which was more potent that cyproheptadine (10 mg/kg) and propranolol (20 mg/kg) which was more potent than cinanserin (10 mg/kg). This rank order of potency differed from that observed for the order of potency of these drugs in inhibiting the myoclonus induced by L-5-hydroxytryptophan (5HTP) plus carbidopa in guinea-pigs (Luscombe, Jenner and Marsden, Neuropharmacology, 1981), perhaps indicating involvement of pharmacologically distinct indoleamine receptors. Manipulation of presynaptic function of 5-hydroxytryptamine (5HT) by tryptophan hydroxylase inhibition with p-chlorophenylalanine to produce depletion of cerebral 5HT, or by an L-tryptophan load to elevate 5HT in brain, suggested that the functional integrity of serotonergic neurones is required for the expression of myoclonus induced by tryptamine plus pargyline. A range of blockers of 5HT re-uptake did not alter the jerking produced by tryptamine (40 mg/kg) in guinea pigs pretreated with pargyline (75 mg/kg; 1 hr previously), or the threshold myoclonus induced by a smaller dose of tryptamine (10 mg/kg; plus pargyline 75 mg/kg). It is suggested that myoclonus induced by tryptamine in guinea pigs pretreated with pargyline involves activation of post-synaptic indoleamine receptors by tryptamine by a mechanism which requires intact presynaptic function of 5HT.
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PMID:Tryptamine-induced myoclonus in guinea-pigs pretreated with a monoamine oxidase inhibitor indicates pre- and post-synaptic actions of tryptamine upon central indoleamine systems. 613 Apr 89

Myoclonus dystonia (M-D) is a hereditary movement disorder caused by a maternally imprinted gene that is often associated with psychiatric symptoms. Most cases of M-D are believed to result from mutations of the epsilon-sarcoglycan protein. The neuroanatomical distribution of epsilon-sarcoglycan-like immunoreactivity in mouse was investigated by using an antiserum against the epsilon-sarcoglycan protein. The expression of epsilon-sarcoglycan mRNA was studied by a sensitive fluorescence in situ hybridization (FISH) method. Immunohistochemistry and FISH revealed a wide distribution of epsilon-sarcoglycan protein and mRNA throughout the mouse brain. High expression levels of epsilon-sarcoglycan mRNA and immunoreactivity were found in the mitral cell layer of the olfactory bulb, the Purkinje cell layer in cerebellum, and the monoaminergic neurons in the mouse midbrain. Immunohistochemistry revealed a similar distribution of epsilon-sarcoglycan protein. Double-labeling FISH showed colocalization of tyrosine hydroxylase and epsilon-sarcoglycan mRNAs within all the midbrain dopaminergic (DAergic) cell groups. By combining FISH with fluorescence immunohistochemistry, coexpression of epsilon-sarcoglycan mRNA and tryptophan hydroxylase immunoreactivity was found in the serotonergic (5-HTergic) neurons within the dorsal raphe nucleus. The distribution of epsilon-sarcoglycan in the mouse brain suggests that the symptom complex of M-D may be related to the effects of decreased epsilon-sarcoglycan activity on the development or function of monoaminergic neurons.
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PMID:Epsilon-sarcoglycan immunoreactivity and mRNA expression in mouse brain. 1561 18