Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of 8-hydroxy-2-(di-n-propyl-amino) tetralin (8-OH-DPAT), 5-methoxy-N,N-dimethyltryptamine (5-MeODMT), buspirone and isapirone were examined at 5-hydroxytryptamine1A (5-HT1A) binding sites and on the 5-HT behavioral syndrome in the rat. 8-OH-DPAT, 5-MeODMT, buspirone and isapirone are all potent inhibitors of 3H-8-OH-DPAT binding to rat brain membranes (Ki values = 1.9-13 nM). However, these drugs have differential effects on the 5-HT behavioral syndrome. 8-OH-DPAT, 5-MeODMT and buspirone induce hindlimb abduction, flattened body posture and Straub tail. Isapirone induces only a slight flattening of body posture. By contrast, 8-OH-DPAT and 5-MeODMT, but not buspirone and isapirone, and isapirone, also induce forepaw treading, head-weaving and tremor. However, both buspirone and isapirone antagonize the induction of these three behaviors by 8-OH-DPAT or 5-MeODMT. These data show that 8-OH-DPAT and 5-MeODMT are "full agonists" in relation to six components of the 5-HT behavioral syndrome. Buspirone and isapirone, on the other hand, act as "antagonists" in relation to forepaw treading, head-weaving and tremor. Therefore, these data suggest that specific components of the 5-HT behavioral syndrome are mediated by 5-HT1A receptors.
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PMID:Differential effects of 5-hydroxytryptamine1a selective drugs on the 5-HT behavioral syndrome. 294 47

Serotonin-induced head shaking behavior, a response associated with 5-HT2 receptors, was examined in rats with lesions of the frontal cortex because of the high density of 5-HT2 receptors in this area. Head shaking behavior caused by the serotonin precursor, 5-hydroxy-L-tryptophan, or by the serotonergic agonist, quipazine, was unchanged following the complete ablation of the frontal cortex. Although 5-HT2 receptors are associated with the head shake response, this behavior is probably not related to serotonin receptors located in the frontal cortex.
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PMID:Serotonin-induced head shaking behavior in rats does not involve receptors located in the frontal cortex. 296 Apr 22

The effects of the 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) on the behaviour of mice were studied. 8-OH-DPAT given i.v. in doses greater than 1 mg/kg induced the distinct 5-HT syndrome, including head weaving, hindlimb abduction, forepaw treading and tremor. The 8-OH-DPAT-induced behaviour was not affected by the 5-HT depleter, p-chlorophenylalanine. Reserpine, which depletes monoamines, significantly decreased the head weaving elicited by 8-OH-DPAT, although it did not reduce the other components of the behavioural syndrome. The non-specific 5-HT receptor antagonist, metergoline, attenuated the 8-OH-DPAT-induced behaviour, while the 5-HT2 receptor antagonist, ketanserin, was without effect. In addition, the 5-HT1A receptor antagonist, spiperone, inhibited the 5-HT syndrome elicited by 8-OH-DPAT, while the dopamine receptor antagonist, haloperidol, affected only the head weaving. These results suggest that 8-OH-DPAT-induced behaviour in mice is mediated by the postsynaptic 5-HT1A receptor.
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PMID:The behavioural effects of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) in mice. 297 71

Brain 5-HT receptors are reported to play an important role in the therapeutic effect of Li in manic-depressive illness. In the present study we examined the effect of Li on 5-HT syndrome which is postulated to be the physiological response of 5-HT1 receptors. Intraperitoneal injection of the 5-HT receptor agonist 5-MeODMT elicited 5-HT syndrome in a dose-dependent manner. Then the incidence of 5-HT syndrome elicited by 2 mg/kg of 5-MeODMT was measured in animals under long-term Li treatment. Four out of six abnormal behaviors of the 5-HT syndrome, i.e. forepaw treading, resting tremor, rigidity, and head weaving, were significantly increased by the 9-day treatment with Li. On the 17th day of Li treatment, the incidence of all six behaviors, including hindlimb abduction and straub tail, were significantly enhanced. This Li-induced supersensitivity of 5-HT1 receptor-mediated behaviors inconsistent with the previous reports of the down-regulation of 5-HT1 receptors measured by receptor binding assay. The reason for this discrepancy is obscure. Further examination of the effect of Li on the signal-transduction system from the receptor to the behavior will be necessary.
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PMID:[Effect of long-term lithium treatment on serotonin syndrome in rats]. 309 11

The actions of the serotonin precursor 5-hydroxytryptophan (5-HTP), the agonist 5-methoxy-N,N-dimetyltryptamine (MeODMT) and quipazine (QPZ) and the antagonists cyproheptadine, methysergide and metergoline, were studied in the rat and in the common marmoset (Callithrix jacchus). The precursor and agonists elicited head shakes, forepaw padding, splayed hindlimbs, tremor and Straub tail in the rat. However, head shakes were not observed after MeODMT and Straub tail was not observed after QPZ. Carbidopa plus 5-HTP potentiated only head shakes, while tranylcypromine (TCP) plus 5-HTP potentiated all the behaviors above. In the marmoset, the action of these drugs elicited drowsiness, teeth chattering, ataxia, vomiting and decreased motor activity, although vomiting was not elicited by MeODMT and ataxia and drowsiness by QPZ. Although TCP plus 5-HTP potentiated all these behaviors, carbidopa plus 5-HTP was not effective. Rats treated with the antagonists (1.0, 5.0 and 10 mg/kg doses) did not show any of these behaviors, but marmosets treated with the same drugs developed "drowsiness", vomiting, and decreased motor activity; nonetheless, cyproheptadine (5.0 and 10 mg/kg doses) did not elicit "drowsiness", while increasing motor activity and the number of head shakes. Pretreatment of marmosets with these antagonists blocked only teeth chattering elicited by MeODMT (4.0 mg/kg) and QPZ (10 mg/kg). Pretreatment with haloperidol, p-chlorophenylalanine and alpha-methyl-P-tyrosine had no effect. The data obtained show that rats and marmosets present differential behavioral responses to the 5-HT drugs used.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Rats and marmosets respond differently to serotonin agonists and antagonists. 311 2

In an open, clinical trial comprising a total of 49 depressed in-patients, a new selective 5-HT uptake inhibitor citalopram was administered by intravenous infusion in doses of 20-60 mg once daily for per 3 weeks. The therapeutic effect was assessed globally and by means of the CPRS subscale for depression (MADRS). About 40 per cent of the patients showed a complete response whereas about 25 per cent showed a partial response. Side effects which were rated globally and recorded according to a check-list were generally mild and infrequent. The side-effects most frequently observed were tremor, drowsiness, and dizziness which occurred in about 15 per cent of the patients.' Three patients were withdrawn prematurely because of nausea and one because of a skin rash. Cardiovascular recordings were normal except for one patient, who developed a hypertension which may have been related to the test drug. No pathological laboratory values were detected during the trial period. The authors conclude that intravenously administered citalopram is well suited for the treatment of depressed patients.
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PMID:[Citalopram. An open study of a highly selective serotonin-uptake inhibitor administered by infusion to depressive patients]. 331 9

Citalopram, a selective 5-HT uptake inhibitor with antidepressant properties, was assessed in three studies in 12 healthy subjects using a battery of EEG, psychological, subjective and symptomatic measures. Study A involved the administration of citalopram, 20 mg and 40 mg, amitriptyline 50 mg and placebo in single dose using a balanced cross-over design. The test battery was applied before, and 1 and 3 h after each drug. Citalopram decreased slow-wave EEG activity whereas amitriptyline increased power in most EEG wavebands. Citalopram increased tapping rate and symbol copying whereas amitriptyline impaired these and other psychomotor tasks. Subjectively, amitriptyline was much more sedative than citalopram and produced more complaints of dry mouth. Study B comprised the administration of citalopram in the usual clinical dose of 40 mg, amitriptyline in the low clinical dose of 75 mg and placebo, each given for 9 nights using a balanced cross-over design. The test battery was applied on the first morning (pre-drug) and on the morning after the last nightly dose. None of the physiological tests showed any drug effects. Subjectively, citalopram was associated with feelings of shaking, nausea, loss of appetite and physical tiredness; amitriptyline produced feelings of shaking, nausea, loss of appetite, dryness of mouth, irritability, dizziness and indigestion; in general, amitriptyline effects were more marked than those of citalopram. Plasma samples were taken on the last day and plasma concentrations of both drugs and their metabolites were found to be in the expected range for the regimens used.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effects of citalopram in single and repeated doses and with alcohol on physiological and psychological measures in healthy subjects. 346 75

The abilities of some naturally occurring beta-carbolines (BCs), dihydro-BCs and tetrahydro-BCs to inhibit the specific binding of 3H-tryptamine (TA), 3H-serotonin (5-HT) and 3H-ketanserine to rat brain membranes and to induce tremor in mice were studied. These compounds, particularly DHBCs and BCs, showed higher affinity for TA binding sites than to 5-HT1 or 5-HT2 binding sites inhibiting the former at nanomolar and the two latter ones at micromolar or high micromolar concentrations. The Ki values for norharmane, harmaline and harmine (17, 18 and 74 nM, respectively) for TA sites indicate the highest affinity so far described for natural beta-carbolines to any receptor sites and thus may indicate their major site of action. among the BC derivatives studied, the before mentioned harmala alkaloids were the most potent inducers of tremor in mice, although the orders of the tremorogenic potency and the binding to TA site did not correlate. It is suggested that especially the tremorigenic effect of BC derivatives is partly based on the binding to specific tryptamine receptors.
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PMID:Tremorigenic effect and inhibition of tryptamine and serotonin receptor binding by beta-carbolines. 356 89

We studied the effect of 3-acetylpyridine (3-AP) lesions on the serotonergic-myoclonic syndromes evoked by quipazine (QP), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), fenfluramine (FF), and p-chloroamphetamine (PCA) in the adult rat. Eleven behaviors were scored from videotapes by an observer blind to drug status. In unlesioned rats, drugs could be differentiated by forelimb and axial myoclonus, pivoting and backing. All drugs significantly suppressed rearing. 3-AP produced a lasting action-enhanced body tremor which differed from axial myoclonus in its vertical direction and rhythmicity. 3-AP lesions modified the effect of drugs on several behaviors, increasing axial (QP, FF, PCA) and forelimb (5-MeO-DMT, FF, PCA) myoclonus and decreasing locomotor score. Prior lesions with 5,7-dihydroxytryptamine did not prevent the effect of 3-AP or any behaviors of the serotonin syndrome, but had a slight effect on the magnitude of forelimb myoclonus, head weaving, and hunching induced by some drugs. Neither lesion abolished or reduced myoclonus. These data suggest that intact 5-HT terminals are not requisite for the tremorogenic and cytotoxic effect of 3-AP. To the extent that chemical lesions with 3-AP are selective for the inferior olive (IO), the role of the IO in myoclonus in several 5-HT rodent myoclonic models appears to be regulatory rather than stimulatory.
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PMID:3-Acetylpyridine lesions and four serotonergic behavioral syndromes in the rat. 356 72

The tremors induced by harmine, LON-954 (N-carbamoyl-2-(2,6-dichlorophenyl)acetamidine hydrochloride) and 5-hydroxytryptophan (5-HTP) were studied in control rats and in rats withdrawn for 16-48 hrs from 6 to 9 days' ethanol administration. The frequencies and the intensities of the tremors were determined electronically. In control rats the frequency spectra of the tremors induced by harmine (20 mg/kg) and LON-954 (10 mg/kg) showed a narrow peak frequency at about 10 Hz. Atropine (1.2 mg/kg) altered neither the frequency nor the intensity of these tremors. 5-HTP (50 mg/kg) when given 3.5 hrs after iproniazid (100 mg/kg) induced tremor with peak frequencies at 6-7 Hz and 12 Hz. In ethanol-withdrawn rats treated with harmine or LON-954 the frequency analysis of tremor revealed a narrow peak frequency at about 12 Hz, which was neither the characteristic frequency of ethanol withdrawal tremor (6 Hz) nor that of harmine or LON-954 (10 Hz). The intensity of both harmine- and LON-954-induced tremor was significantly increased in ethanol-withdrawn rats. The ethanol-withdrawn rats were markedly sensitized to the effect of iproniazid+ 5-HTP, shown by deaths. The peak frequencies of this tremor were the same as those in control rats. The results suggest that harmine-induced tremor involves a dopaminergic-5-HT'ergic imbalance and the tremor induced by LON-954 a dopaminergic-cholinergic imbalance in the brain. The tremor in ethanol-withdrawn rats seems to be mediated by alterations in the activity of the cerebral 5-HT'ergic system.
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PMID:Harmine-, LON-954- and 5-hydroxytryptophan-induced tremors in rats withdrawn from ethanol. 387 87


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