Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Metaphit, which acylates phencyclidine (PCP) receptors in vitro, was shown to acylate PCP receptors and antagonize the behavioral and electrophysiological effects of PCP in vivo. Metaphit (2 mumol/rat) administered i.c.v. produced PCP-like stereotyped behavior and ataxia in 10 to 20% of rats. At a lower dose, Metaphit (1 mumol/rat) antagonized the ability of PCP to induce stereotyped behavior and ataxia for 3 and 4 days, respectively. The Metaphit-induced antagonism of PCP induction of stereotyped behavior and ataxia was dose-dependent and specific as Metaphit did not antagonize induction of stereotyped behavior by amphetamine. Further evidence for a specific PCP receptor mechanism was the finding that PCP pretreatment blocked the effects of subsequent Metaphit administration. Metaphit also antagonized PCP-induction of stereotyped behavior, but not ataxia, after i.v. administration. Doses of Metaphit that produced long-term antagonism of the behavioral effects of PCP also produced a significant decrease in the maximum binding, but not Kd, of the binding of the PCP analog, [3H]-1-(2-thienyl)cyclohexyl]piperidine, in Metaphit-pretreated rats. The binding of [3H]etorphine and [3H]spiroperidol was not altered significantly by pretreating rats with Metaphit. (-)-Cyclazocine and (+)-SKF 10,047 induced stereotyped behavior and ataxia that was not antagonized by Metaphit-pretreatment. In electrophysiological experiments, Metaphit, like PCP, initially depressed the firing of caudate neurons as does PCP, but then irreversibly inhibited PCP-induced depression of caudate neurons. These results suggest that metaphit antagonized the effects of PCP by selectively acylating PCP receptors and that (-)-cyclazocine- and (+)-SKF 10,047-induced behavioral effects are not mediated primarily by PCP receptors.
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PMID:Metaphit, an acylating ligand for phencyclidine receptors: characterization of in vivo actions in the rat. 301 19

Electrophysiological and behavioral methods were used to evaluate the effects of chronic exposure to phencyclidine (PCP, 5 mg/kg/day for 30 days) on ventral tegmental A10 dopaminergic neurons and locomotor and ataxic behavior in the rat. Extracellular recordings from single neurons in the ventral tegmentum showed only minimal differences between rats chronically treated with either saline or PCP. A comparison of the rising portion of the cumulative dose-response curves indicated that the animals treated chronically with the drug required only 0.4 times more PCP than the controls to produce equivalent changes in neuronal firing rates. Also, the average maximum increase in activity in A10 neurons, induced by PCP, was 43% in the drug-treated rats compared to 60% in the controls. Although these were moderate quantitative changes, a marked qualitative difference in the response of A10 neurons to PCP was seen. Whereas PCP elicited a characteristic dose-dependent biphasic effect on the firing rates in the control group, the declining (inhibitory) component of the response was not present in the animals chronically treated with PCP. In parallel with the minimal electrophysiological changes, measurements of gross locomotor activity showed that the response to the thirtieth (30th) injection of PCP was virtually identical to that measured in the same animals following the first exposure. In contrast, however, the ataxia which accompanied the hyperactivity rapidly diminished over the course of treatment. It would appear, therefore, that chronic exposure to PCP did not substantially diminish the ability of PCP to activate the A10 neurons, comprising the mesocorticolimbic dopaminergic systems.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of acute and chronic administration of phencyclidine on the A10 dopaminergic mesolimbic system: electrophysiological and behavioral correlates. 321 58

Brown oxidation of cis-bicyclo[3.1.0]hexan-3-ol afforded bicyclo[3.1.0]hexan-3-one in 98% yield. Treatment of this ketone with either phenyllithium or phenylamagnesium bromide in ether at room temperature followed by solvolysis of the resulting alcohol in a mixture of trifluoroacetic acid, sodium azide, and chloroform gave a mixture of cis- and trans-3-azido-3-phenylbicyclo[3.1.0]hexanes. LAH reduction of this crude mixture of azides afforded a 1:3.5 mixture of cis- and trans-3-phenyl-3-bicyclo[3.1.0]hexylamine, respectively, in 51% overall yield from the alcohol. Separation of the mixture of amines by column chromatography followed by cyclization of each by heating at 60 degrees C in DMF solution with 1 equiv of 1,5-dibromopentane furnished the two conformationally restrained analogues of phencyclidine (PCP), cis- and trans-3-phenyl-3-piperidinylbicyclo[3.1.0]hexane (1 and 2, respectively), in high yield. Configurations were assigned on the basis of an X-ray crystallographic analysis of the cis isomer (1). Bond lengths and angles are similar to those found in PCP and its derivatives. Binding to PCP receptors and sigma sites as well as behavioral effects of 1 and 2 in rats was determined relative to PCP. In displacement of specifically bound [3H]TCP (1-[1-(2-thienyl)cyclohexyl]piperidine) from PCP receptors, 1 and 2 were nearly equipotent and about one-seventh as potent as PCP. These compounds were about one-fifth as potent as PCP in displacing [3H]-(+)-SKF 10,047 from its binding site. Calculation of the ED50 values of 1 and 2 for stereotyped behavior and ataxia indicated that they were about equipotent, and 2-3-fold less active than PCP.
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PMID:Synthesis, configuration, and evaluation of two conformationally restrained analogues of phencyclidine. 339 94

The effects of chronic phencyclidine (PCP) or ketamine (KET) on their respective acute behavioral and anticonvulsant actions were investigated. Female rats were treated for 15 days with twice daily i.p. injections of saline, 20 mg/kg PCP or 40 mg/kg KET. Subjects treated chronically with PCP were challenged with either 10 mg/kg or 20 mg/kg i.p. PCP, while subjects treated chronically with KET were challenged with 40 mg/kg i.p. KET only. Neither chronic drug treatment induced tolerance to the acute anticonvulsant effect, nor to hyperlocomotion and stereotypy as measured by automated activity monitors. However, evidence of tolerance to the stereotypy induced by acute KET was obtained when an observer-based rating scale was employed. In addition, tolerance occurred to the ataxia induced by KET and the 10 mg/kg, but not 20 mg/kg, dose of PCP. Thus, tolerance occurs to some of the acute behavioral effects of PCP and KET while the anticonvulsant action of these compounds remains unaffected.
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PMID:The anticonvulsant and behavioral effects of phencyclidine and ketamine following chronic treatment in rats. 379 Feb 47

Five infants and two young children were treated at a large children's hospital for phencyclidine intoxication. The clinical symptoms and signs were mostly neurologic, including diminished response to tactile and verbal stimuli (100%), ataxia (71%), nystagmus (57%), constricted pupils (57%), depressed sensorium, and stupor associated with a blank, expressionless stare (57%). Notably absent were the behavioral aberrations such as aggression, which are usually seen with PCP intoxication in older children and adults. The possibility of drug intoxication was denied by most of the parents or surrogate parents accompanying these small children and infants for treatment. It is suggested that a systematic investigation for possible PCP exposure, including a urine toxicology screen for PCP (preferably by immunoassay methods), be conducted whenever an infant or child is brought for emergency treatment of unresponsiveness, bizarre behavior, dyskinesis, dystonic posturing, atypical oculomotor and pupil findings, or evidence of hallucinations.
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PMID:PCP intoxication in seven young children. 379 69

The effects of acute and chronic phencyclidine (PCP) administration on neurotensin-like immunoreactivity (NTLI) were investigated in discrete regions of rat brain. Both acute and chronic administration of PCP induced high locomotor activity, stereotypy and ataxia. On PCP administration, NTLI decreased significantly in the frontal cortex (Fc) alone. These results suggest that the decrease in NTLI in Fc is related to the behavioral abnormalities produced by PCP.
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PMID:Effects of phencyclidine administration on behavior and brain neurotensin-like immunoreactivity in rats. 403 20

The dose-response effects of neuroleptic pretreatment on phencyclidine (PCP; 3 or 5 mg/kg)-induced locomotor activity, stereotyped behaviors and ataxia were quantified in groups of male rats using rating scales recently developed in this laboratory. Three butyrophenone neuroleptics consistently produced dose-dependent antagonism of the behavioral effects of PCP administration. Fluphenazine antagonized the behavioral effects produced by 3 mg/kg PCP but not those produced by 5 mg/kg PCP. Each of the other neuroleptics examined (chlorpromazine, thioridazine, mesoridazine, triflupromazine, cis-flupenthixol) had no consistent antagonistic effect or actually enhanced one or more of the behavioral effects of PCP. Some neuroleptics slightly reduced PCP locomotion or stereotypies at high doses, but these effects were probably a non-specific consequence of the synergistic ataxia-producing properties of these drugs. In a second set of experiments, atropine sulfate pretreatment increased PCP-induced locomotor activity and stereotyped behaviors but had no effect on ataxia; pretreatment with physostigmine produced opposite effects. Combined pretreatment with haloperidol and atropine sulfate significantly reduced only haloperidol antagonism of PCP-induced ataxia, thus suggesting that non-dopoaminergic effects of neuroleptics may interfere with their ability to antagonize PCP.
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PMID:A comparison of the effects of neuroleptics on phencyclidine-induced behaviors in the rat. 611 21

Studies on the effects of PCP have been conducted in volunteers in the Army Laboratories and elsewhere and in illicit users. The present review has summarized the observations of many investigators which showed that the acute effects of PCP following several routes of administration were shown to be dose-related. High doses of PCP produce disturbing manifestations including psychosis, numbness, light-headedness, vertigo, ataxia, and nystagmus due to acute intoxication. Furthermore, some subjects became irritable, argumentative or negative under the conditions of social stress and demanding tasks. In addition to a variety of central action, PCP has also been shown to affect cardiovascular function, heat storage, and exercise performance. PCP can also induce, although rarely, prolonged toxic psychosis in chronic abusers and precipitate psychotic episodes in psychotic and prepsychotic personalities. Tolerance, but not physical dependence, develops to the effects of PCP. Psychologic dependence as indicated by craving for the drug has however been reported.
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PMID:Phencyclidine (PCP): some human studies. 651 53

This study was designed to assess the sex differences in phencyclidine(PCP)-induced ambulatory activity in an open-field, stereotyped behaviors, motor incoordination, tremor, salivation, the regional and subcellular distributions of PCP in the brain and the half-life of PCP in the brain and plasma. Female rats appeared to be more sensitive to PCP as evidenced by hyperactivity, stereotyped behaviors, motor incoordination, tremor, salivation and ataxia. The concentrations of PCP in female rat brain were higher than in the male rats in some discrete brain areas and subcellular fractions. The half-life of PCP in the brain and plasma was longer in female rats than in male rats. The inverse relationship of pharmacological responses to PCP and biotransformation of PCP in both sexes of rats suggests that sex differences in pharmacological actions of PCP depend largely on differences in ability to biotransform the drug.
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PMID:Sex-dependent differences in the pharmacological actions and pharmacokinetics of phencyclidine in rats. 653 6

The effects of phencyclidine (PCP) (7.0, 11.7, 19.5, 32.6, and 54.4 mg/kg) on locomotor activity, stereotyped behavior (circling, backing up, and weaving frequency), and rotarod performance were evaluated. In addition, the frequency of other PCP-induced abnormal behaviors (head in corner, arched back, and cataleptic freeze) was determined. All doses of PCP produced a significant increase in locomotor activity and stereotyped behavior as well as an impairment of rotarod performance. Both the duration and the time to peak effects (with the exception of rotarod performance) of these PCP-induced behavioral changes appeared to be dose dependent. The delay in attaining peak effects for locomotor activity and stereotypy was attributed to PCP-induced gross motor ataxia, which became more severe and long lasting with increasing dose. Although the longest period of time that significant changes were seen in locomotor activity, stereotyped behavior, and rotarod performance was 12 hr, sporadic recurrences of stereotypy and a significant increase in cataleptic freeze were observed in the high-dose groups (19.5, 32.6, and 54.4 mg/kg) up to 21 days postadministration. These persistent behaviors (stereotypy and cataleptic freeze) are not unlike certain of the prolonged behaviors seen in man with PCP overdose (catatonic stupor along with repetitive orofacial and limb movements).
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PMID:The effect of a single administration of phencyclidine on behavior in the rat over a 21-day period. 654 Sep 2


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