Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.16.2 (PCP)
 3,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

[3H]Phencyclidine (PCP) bound specifically and with high affinity (Kd = 0.15 microM at pH 7.4) to a single saturable class of binding sites in rat brain membrane preparations. Specific binding constituted approximately 70% of total binding at 0 degrees C and 33% of total binding at 37 degrees C (at 10 nM [3H]PCP). Bound [3H]PCP could be displaced by nonradioactive PCP, a series of its derivatives, and the psychotomimetic opiate N-allylnorcyclazocine (SKF 10,047) with relative potencies that closely paralleled those determined in animal behavioral tests. Muscarinic cholinergic ligands inhibited [3H]PCP binding, but only at 0.1 mM and in rank order at variance with that for binding to muscarinic sites or for pharmacological potencies. Other drugs, including opiates other than SKF 10,047, were unable to displace specifically bound [3H]PCP at 0.1 mM. [3H]PCP binding was most enriched in crude synaptosomal subcellular fractions, and was about three times higher in hippocampus (region of highest density) than in cervical spinal cord (region of lowest density). Trypsin and Pronase reduced specific [3H]PCP binding. Thus, PCP may exert its effects on the central nervous system via binding to specific brain receptor sites.
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PMID:Specific [3H]phencyclidine binding in rat central nervous system. 29 53

Fifty patients with P. carinii pneumonitis were randomized to receive either pentamidine isethionate or trimethoprim-sulfamethoxazole therapy. Those not responding favorably to the first drug after three or more days of therapy were changed to the alternate drug. Of the 26 patients initially treated with TMP-SMZ, 20 recovered (0.77)-17 after TMP-SMZ alone and three of nine who were crossed over to pentamidine. Of the 24 patients initially treated with pentamidine, 18 recovered (0.75)-14 of 15 who received only pentamidine and four of nine who were crossed over to TMP-SMZ. Abnormal values for blood urea nitrogen, creatinine, or glucose; inflammation at injection sites; or combination of these effects occurred in 14 of the 15 patients treated with pentamidine alone. Only one of the 17 patients treated with TMP-SMZ alone developed any of these abnormalities. This study shows that TMP-SMZ is as effective as pentamidine in the treatment of PCP, and that it offers the advantages of minimal adverse effects, oral administration, and ready availability.
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PMID:Comparison of pentamidine isethionate and trimethoprim-sulfamethoxazole in the treatment of Pneumocystis carinii pneumonia. 30 78

The history, symptoms, diagnosis and treatment of phencyclidine hydrochloride (PCP) intoxication and the pharmacology of PCP are reviewed. Intoxication with low to moderate doses of PCP (5-20 mg) resembles an acute, confusional state generally lasting four to six hours. High doses (greater than 20 mg) may cause serious neurologic and cardiovascular complications and the patient is often comatose for several days. Treatment involves supportive psychological and medical measures. Evacuation of the stomach with activated charcoal and a saline cathartic may be indicated and succinylcholine chloride may ease intubation. Diazepam and chlorpromazine may be used to control the combative patient and the "PCP psychosis" patient, respectively. Antihypertensive agents are not usually needed, but diazoxide and hydralazine hydrochloride have been used to treat hypertensive crises. Diazepam and phenytoin have been used to treat seizures. Ion-trapping by continuous gastric suctioning and by urine acidification with ammonium chloride may increase clearance of PCP. Forced diuresis with furosemide in conjunction with acidification may further increase PCP clearance. Use of physostigmine is based on conjecture.
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PMID:Phencyclidine intoxication: a literature review. 36 Aug 32

The effects of acute and chronic administration of phencyclidine (PCP) were examined in five male squirrel monkeys trained to respond on a chain fixed-interval fixed-ratio schedule of food presentation. Acute PCP (0.01-0.60) mg/kg i.m.) produced dose-related decreases in response rate during both components of the schedule. Both components were equally affected by the drug. The effects of the drug on fixed-interval response rate were dependent on the control rate of responding in corresponding segments of the interval. After the initial dose-response determination, the subjects were placed on an individualized regimen of chronic PCP administration lasting from 82 to 126 days, beginning with daily injections for 2 days alternating with saline injections for 2 days, progressing to four injections daily. No evidence of physical dependence was seen upon withdrawal of the drug. Redetermination of the dose-response function for PCP (0.03-1.0 mg/kg i.m.) demonstrated a nearly 2-fold shift to the right of both the fixed-interval and fixed-ratio dose-response curves, indicating tolerance. In addition, the subjects' behavior recovered sooner from a dose of PCP (0.60 mg/kg i.m.) given after the chronic regimen than from the same dose given before the chronic regimen. The results demonstrate that tolerance can occur to the behavioral effects of PCP in the squirrel monkey.
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PMID:The effects of acute and chronic phencyclidine on schedule-controlled behavior in the squirrel monkey. 41 49

The distribution and metabolic fate of several rice paddy pesticides were evaluated in a modified model ecosystem. Among the three BHC isomers, beta-isomer was the most stable and bioconcentrated in all of the organisms. Alpha- and gamma-isomers were moderately persistent and degraded to some extent during the 33 day period. Disulfoton was relatively persistent due to the transformation to its oxidation products. Pyridaphenthion was fairly biodegradable. N-Phenyl maleic hydrazide derived from the hydrolysis of pyridaphenthion was not detected in the organisms though it was found in the aquarium water after 33 days. Cartap and edifenphos were considerably biodegradable, and the ratio of the conversion to water soluble metabolites was very high. There was a distinct difference in the persistence of Kitazin P and edifenphos in the aquarium water. It appeared that the hydrolysis rate of the pesticides affected their fate in the organisms. PCP appeared to be moderately biodegradable. CNP was considerably stable and stored in the organisms though the concentration in the aquarium water was relatively low. The persistence and distribution of the pesticides in the model ecosystem were dependent on their chemical structures. In spite of the limitation derived from short experimental period, the model ecosystem may be applicable for predicting the environmental fate of pesticides.
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PMID:Environmental fate of rice paddy pesticides in a model ecosystem. 43 58

Phencyclidine (PCP) is a potent sympathomimetic and hallucinogenic dissociative anesthetic agent. As an abused street drug, it is most often smoked, thus allowing the user to titrate the dose. The clinical signs of PCP intoxication can be viewed in three dose-related stages, but waxing and waning of signs through the three stages is not uncommon. Treatment protocols for each stage address drug therapy and both clinical and psychological supportive measures.
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PMID:Emergency management of acute phencyclidine intoxication. 43 46

PCP and its new metabolites persisted for very prolonged periods in rat brain and adipose tissue after a single 25 mgkg-1 intraperitoneal injection and showed accumulation after multiple dosing. The brain to plasma ratios for PCP between 0.5 h to 48 h after injection ranged between 6 to 8.8 and adipose tissue to plasma ratios between 31 to 113. The concentrations of metabolites of PCP in rat brain (ng-eqt/g. tissue) 1, 2 and 3 weeks after a single 25 mgkg-1 i.p. injection of PCP were approximately 390, 230 and 74 respectively and those of PCP 12, 6 and 5 ng/g. respectively. The long sojourn of PCP in adipose tissue and relatively slow egress therefrom explains cumulative effects upon multiple dosing and raises the possibility of mobilisation or release of large amounts of drug from fat stores in situations involving food deprivation, marked weight loss or stress. The persistence of PCP and its metabolites in brain and high degree of binding with melanin, implying a possible localisation in neuromelanin-rich substantia nigra of midbrain and locus coeruleus of pons may help explain the prolonged duration of clinical effects and persistent neurological and cognitive dysfunction several days after PCP administration.
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PMID:Persistence of phencyclidine (PCP) and metabolites in brain and adipose tissue and implications for long-lasting behavioural effects. 45 33

A sensitive and specific radioimmunoassay has been developed for the drug phencyclidine (PCP). Levels as low as 50 pg (200 femto-moles) of PCP can be detected. The specificity of the antisera has been investigated by inhibiting the [3H]PCP-anti PCP reaction with the parent drug, metabolites, and other related compounds. Three urinary metabolites, 4-phenyl-4-piperidinocyclohexanol, 1-(1-phenylcyclohexyl)-4-hydroxypiperidine and 1-phenylcyclohexylamine inhibit 2,5, and 0.002% as effectively as PCP respectively. Plasma samples supplemented with PCP (1.2 to 10,000 ng/ml) can be analyzed directly by this procedure.
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PMID:Radioimmunoassay for phencyclidine. 50 90

Violence associated with chronic phencyclidine (PCP) abuse was investigated by administering a structured interview to 16 chronic PCP abusers. A more intensive study was done of another individual who committed murder and self-mutilation under the influence of PCP. The results suggest that there is no consistent association between PCP-related violence and a history of violence not related to drug or alcohol abuse. The author defines four types of violence associated with chronic PCP abuse.
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PMID:Violence associated with phencyclidine abuse. 50 11

Phencyclidine (PCP) impaired spatial alternation performance in rats. This effects was mimicked by antimuscarinic anticholinergics (scopolamine, atropine) and PCP derivatives (ketamine, cyclohexamine) but not by a variety of other agents. Muscarinic cholinergic agonists antagonized PCP. Impairment of spatial alteration performance by PCP appears to be mediated, at least in part, by and anticholinergic action; this is the first instance of a behavioral effect of PCP that can be largely attributed to a specific mechanism.
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PMID:Anticholinergic behavioral effect of phencyclidine. 51 Mar 89


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