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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)
A series of eight C5-substituted analogues of (+-)-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (1) have been prepared by the directed lithiation-alkylation (and acylation) of its (+-)-N-tert-butylformamidinyl derivative 2 followed by formamidine solvolysis. An additional 10 analogues were prepared by elaboration of the C5-ethyl ester derivative. Analogues possessing large (e.g. propyl and larger) lipophilic substituents displace [3H]-1-(1-thienylcyclohexyl)
piperidine
[( 3H]TCP) from the high-affinity phencyclidine (
PCP
) binding site in rat brain homogenates only at high concentrations (Ki greater than 1000 nM); however, the presence of a polar amino functionality (e.g. 2-aminoethyl) offsets this effect (Ki = 20 nM). Thus, the boundary condition for lipophilic substituents larger than ethyl appears to be polar in nature. Interaction of the 11 relatively small (MR less than 14) C5-substituted analogues of 1 with the high-affinity
PCP
binding site associated with the N-methyl-D-aspartate (NMDA) receptor is best described by the equation log (1/Ki) = -5.83F + 0.64 pi + 7.41 (r = 0.90).
...
PMID:Synthesis and structure-activity relationship of C5-substituted analogues of (+-)-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine [(+-)-desmethyl-MK801]: ligands for the NMDA receptor-coupled phencyclidine binding site. 215 20
Scratching induced by intrathecal (IT) administration of kainic acid (0.5 nmol) to rats was inhibited by IT pretreatment with the selective mu agonists levorphanol (30 and 90 nmol), [D-Ala2,N-Met-Phe4,Gly5-ol]-enkephalin (DAGO, 0.4 and 1.1 nmol), or morphine (90 nmol), the mixed mu-delta agonist [D-Ala2,D-Leu5]-enkephalinamide (DADLE, 10 and 30 nmol), or the sigma/phenycyclidine (
PCP
) agonists dextrorphan (90 nmol) or (+)-N-allyl-N-normetazocine ([+]-NAM, 90 nmol). The kappa agonists dynorphin (1.1 nmol) and ethylketocyclazocine (EKC, 90 nmol) had no significant effect, nor did the selective delta agonist [D-Pen2,D-Pen5]-enkephalinamide (DPDPE, 90 nmol). The nonopioids (+)-3-(3-hydroxyphenyl)-N-(1-propyl)
piperidine
([+]-3-PPP, 90 nmol) and
PCP
(90 nmol), selective for sigma and
PCP
sites, respectively, both antagonized kainic-induced scratching. Levorphanol- and DADLE-induced attenuation of scratching was partially antagonized by naltrexone. These findings suggest that opioid inhibition of kainic acid-induced scratching is mediated by classical mu receptors as well as sigma and
PCP
sites.
...
PMID:Opioid inhibition of kainic acid-induced scratching: mediation by mu and sigma but not delta and kappa receptors. 215 73
The kinetic and equilibrium binding of various tritiated phencyclidine (
PCP
)-like drugs to the N-methyl-D-aspartate (NMDA) receptor of rat brain cortex were analyzed and compared. The tested drugs showed the following rank order of affinity toward the receptor: [3H](+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imi ne maleate ([3H]MK-801) greater than [3H]-N-[1-(2-thienyl)cyclohexyl]
piperidine
([3H]TCP greater than [3H]-N[1-(3-aminophenyl)cyclohexyl]
piperidine
([3H]NH2PCP) greater than [3H]phencyclidine ([3H]
PCP
) greater than [3H]-N[1-(3-azidophenyl)cyclohexyl]
piperidine
([3H]AZ-
PCP
) greater than [3H]-N-[1-(3-nitrophenyl)cyclohexyl]
piperidine
([3H]NO2PCP) (Kd = 3, 10, 24, 35, 100 and 2500 nM, respectively). All of the labeled ligands were found to associate with and dissociate from the receptor; both processes occurred at relatively slow rates in the absence of added glutamate and its allosteric effector glycine (basal binding) but were markedly accelerated upon their addition. For each drug, the basal association rate was similar to the basal dissociation rate. However, the basal rates differed markedly among the different drugs tested, and their apparent time constants characterizing the first-order process of basal ligand binding (kb) correlated inversely with their equilibrium binding constants (KD). The recorded kb values (10(-3) min-1) were 2.3, 5.1, 12.4, 44 and 79 for [3H]MK-801, [3H]TCP, [3H]NH2PCP, [3H]
PCP
and [3H]AZ-
PCP
, respectively. The glutamate- and glycine-induced dissociation rates (characterized by the apparent time constant k-1) differed among the ligands and also correlated inversely with their KD values. Their induced association rates, however, were similar.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Distinctive structural requirement for the binding of uncompetitive blockers (phencyclidine-like drugs) to the NMDA receptor. 215 15
Phencyclidine (
PCP
) binds with high affinity to two receptors in rat brain--the
PCP
receptor and the Sigma receptor. Although both receptors are present prenatally, and their number increases postnatally, their rate of increase, compared to the increase in brain protein, is quite different, yielding distinct ontogenic profiles. Thus,
PCP
receptors are present on prenatal day 2 and show a further 15-fold increase by postnatal day 28. In contrast, Sigma receptors are present at their highest density during the perinatal period, and decline thereafter. The Kd of the
PCP
receptor for TCP remains constant throughout development, whereas the Kd of the Sigma receptor for (+)-3-(3-hydroxyphenyl)-N-(1-propyl)
piperidine
decreases 40% postnatally. On postnatal day 6, both
PCP
and Sigma receptors display a pharmacological profile similar to that observed in adult animals.
...
PMID:Ontogeny of PCP and sigma receptors in rat brain. 215 61
Several lines of evidence suggest a tight functional coupling between N-methyl-D-aspartate (NMDA) and phencyclidine (
PCP
) receptors. The effects of
PCP
receptor agonists (
PCP
, dexoxadrol, ketamine and MK-801) and NMDA receptor antagonists, cis-4-phosphonomethyl-2-
piperidine
carboxylic acid (CGS-19755) and 3-(2-carboxypiperizin-4-yl)-propyl-1-phosphonic acid (CPP), have been examined on the metabolism of dopamine in the mesocortex, with a view of studying the coupling between these two receptor systems. Phencyclidine receptor agonists selectively increased the metabolism of dopamine in the mesocortex without affecting the metabolism of dopamine in the striatum. N-Methyl-D-aspartate and the competitive antagonists of NMDA receptors did not effect the metabolism of dopamine, neither did the sigma receptor ligands, 1,3-di-(2-tolyl)guanidine (DTG) and rimcazole. Rimcazole also did not affect the increases in the metabolism of dopamine in the mesocortex, seen after MK-801. These data indicate that dopaminergic neurons in the mesocortex are positively modulated by
PCP
receptors but tentatively suggest that those recognition sites for
PCP
are not coupled to NMDA receptors.
...
PMID:Selective activation of dopaminergic pathways in the mesocortex by compounds that act at the phencyclidine (PCP) binding site: tentative evidence for PCP recognition sites not coupled to N-methyl-D-aspartate (NMDA) receptors. 215
The functional effects of sigma and
PCP
receptor ligands were examined in the perfused rat tail artery. The following ligands were studied: haloperidol; (+)-3-PPP [(+)-3-(3-hydroxyphenyl)-N-(1-propyl)
piperidine
]; (+-)-BMY 14802 [(+-)-alpha-(4-fluorophenyl)-4-(5-fluoro-2-pyrimidinyl)-1-piperazine butanol]; DTG [1,3-di-orthotolyl-guanidine]; rimcazole (BW 234U) [cis-9-[3-(3,5-dimethyl-1-piperazinyl)propyl]carbazole dihydrochloride]; (+)-SKF 10047 [(+)-N-allyl-N-normetazocine]; TCP, [1-[1-(2-thienyl)cyclohexyl]
piperidine
]; and MK 801 [(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate]. (+)-3-PPP, (+)-SKF 10047, MK 801 and TCP potentiated contractile responses to norepinephrine, an effect which was blocked by cocaine implying an action of these agents on monoamine uptake. In the presence of cocaine an additional postjunctional inhibitory action of (+)-3-PPP and (+)SKF 10047 on norepinephrine-induced contractile responses was unveiled. In contrast, haloperidol, (+/-)-BMY 14802, rimcazole and DTG inhibited contractile responses to norepinephrine. Haloperidol, (+/-)-BMY 14802 and (+)-SKF 10047 (+ uptake blockade) also inhibited contractile responses to serotonin. The order of potency for inhibition of norepinephrine-induced contractions was haloperidol greater than (+/-)-BMY 14802 greater than (+)-3-PPP greater than rimcazole greater than (+)-SKF 10047 (+ uptake blockade) greater than DTG. These studies demonstrate the lack of selectivity of many sigma and
PCP
ligands, significant effects on norepinephrine uptake, as well as the potential utility of the rat tail artery to explore the functional properties of these ligands.
...
PMID:Multiple vascular effects of sigma and PCP ligands: inhibition of amine uptake and contractile responses. 215 42
The N-methyl-D-aspartate (NMDA)/phencyclidine (
PCP
) receptor from rat forebrain was solubilized with sodium cholate and purified by affinity chromatography on amino-
PCP
-agarose. A 3700-fold purification was achieved. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and dithiothreitol revealed four major bands of Mr 67,000, 57,000, 46,000, and 33,000. [3H]Azido-
PCP
was irreversibly incorporated into each of these bands after UV irradiation. The dissociation constant (Kd) of [1-(2-thienyl)cyclohexyl]
piperidine
[( 3H]TCP) binding to the purified NMDA/
PCP
receptor was 120 nM. The maximum specific binding (Bmax) for [3H]TCP binding was 3.3 nmol/mg of protein. The pharmacological profile of the purified receptor complex was similar to that of the membranal and soluble receptors. The binding of [3H]TCP to the purified receptor was modulated by the NMDA receptor ligands glutamate, glycine, and NMDA.
...
PMID:N-methyl-D-aspartate/phencyclidine receptor complex of rat forebrain: purification and biochemical characterization. 215 97
The phencyclidine (
PCP
) derivative N-[1-(2-thienyl)cyclohexyl]-
piperidine
(3H-TCP) was used to label in vivo the N-methyl-D-aspartate (NMDA) receptor-associated ionic channel in the mouse brain. After the injection of a tracer dose of 3H-TCP, a spread labeling throughout the brain was observed, but was the highest in the cerebellum. Preadministration of unlabeled TCP (30 mg/kg) resulted in a 90% reduction of 3H-TCP binding.
PCP
, TCP, MK-801, dexoxadrol, ketamine, and SKF 10,047 isomers dose-dependently prevented the in vivo 3H-TCP binding. ID50 determined in the cerebrum and the cerebellum were respectively correlated with K0.5 for 3H TCP high (rat cortex) and low affinity (rat cerebellum) sites in vitro. The pharmacological specificity of the 3H-TCP binding site in the cerebellum was significantly different from that in the cerebrum. ID50 values were generally higher than in the cerebrum and, particularly, MK-801, the most potent drug in the cerebrum, was without significant effect in the cerebellum, at any time and at doses as high as 30 mg/kg. N-[1-(2-benzo(b) thiophenyl)cyclohexyl]
piperidine
(BTCP), desipramine, and atropine showed a more efficient prevention of 3H-TCP binding in the cerebellum than in the cerebrum. The prevention of the binding by TCP or
PCP
, at doses close to their ID50 values, was rapid and then decreased slowly. The effect of MK-801 was long-lasting. This study confirm previous in vitro studies: 3H-TCP is an efficient tool for the labeling of the NMDA receptor-associated ionic channel.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:In vivo labeling of phencyclidine (PCP) receptors with 3H-TCP in the mouse brain. 216 51
Certain benzeneacetamides [(-)- and (+)-cis-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl) cyclohexyl]benzeneacetamide] were recently reported to be potent sigma receptor ligands. In order to determine whether efficacy for the sigma receptor could be improved, a series of compounds related to the benzeneacetamides, N-substituted cis-2-(1-pyrrolidinyl)-N-methylcyclohexylamines, were synthesized and their structure-activity requirements were determined. The compounds were synthesized by starting with the previously reported (+/-)-, 1S,2R-(+)-, and 1R,2S-(-)-cis-2-(1-pyrrolidinyl)-N-methylcyclohexylamines. Analysis of sigma ([3H](+)-3-PPP), kappa ([3H]bremazocine and [3H]U69,593), dopamine-d2 ([3H](-)-sulpiride), and phencyclidine (
PCP
) ([3H]TCP) receptor binding in guinea pig brain revealed a number of highly potent and selective sigma receptor ligands. Notably, 1S,2R-cis-(-)-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-(2-naphthyl) acetamide [(-)-29] (Ki = 8.66 +/- 0.35 nM), (+/-)-cis-2-amino-4,5-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl] benzeneacetamide [(+/-)-17] (Ki = 11 +/- 3 nM), 1S,2R-(-)-cis-N-methyl-N-[2-(3,4-dichlorophenyl)ethyl]-2-(1-pyrrolidinyl ) cyclohexylamine [(-)-44] (Ki = 1.3 +/- 0.3 nM), and 1R,2S-(+)-cis-N-methyl-N-[2-(3,4-dichlorophenyl)ethyl]-2-(1-pyrrolidinyl ) cyclohexylamine. [(+)-44] (Ki = 6 +/- 3 nM) exhibited very high affinity at sigma receptors, by displacement of [3H]-(+)-3-(3-hydroxyphenyl)-N-(1-propyl)
piperidine
[( 3H]-(+)-3-PPP). These compounds showed insignificant affinity for kappa, dopamine, or
PCP
receptors, making them valuable tools for the study of sigma receptors. Furthermore, these compounds also exhibited enantioselectivity ranging from 5-fold for (+)- and (-)-44 to 160-fold for (+)- and (-)-29. Several other compounds showed equivalent selectivity but displayed lower sigma receptor affinity.
...
PMID:Synthesis and evaluation of N-substituted cis-N-methyl-2-(1-pyrrolidinyl)cyclohexylamines as high affinity sigma receptor ligands. Identification of a new class of highly potent and selective sigma receptor probes. 217 38
The postnatal development of the three receptor binding sites that constitute the N-methyl-D-aspartate (NMDA) receptor channel/complex was examined in six hippocampal regions of rats using quantitative receptor autoradiography. NMDA-sensitive [3H]-glutamate binding, strychnine-insensitive [3H]glycine binding, and [3H]N-(1-[2-thienyl]cyclohexyl)-3,4-
piperidine
[( 3H]TCP) binding were measured to examine the ontogeny of NMDA recognition sites, glycine modulatory sites, and
PCP
receptors, respectively. NMDA-sensitive [3H]glutamate binding transiently exceeded adult levels by 50 to 120% in all regions examined, with peak densities generally occurring between postnatal days (PND) 10 and 28. Stratum radiatum CA1 binding increased slowly from 49 to 61% of the adult value between PND 1 and 7, after which, binding rapidly rose to 151% of adult values at PND 14, remained elevated through PND 28, and then decreased to adult levels. The ontogenic profile of NMDA recognition site binding was similar in other hippocampal regions, although the initial age of maximal binding and the period of stabilization varied. The ontogenic profiles of glycine modulatory site binding and
PCP
receptor binding were very similar to each other. Development was delayed, however, with respect to NMDA recognition site binding. The rapid development of binding observed between PND 7 and 14 with NMDA receptors in stratum radiatum CA1 was contrasted by a much slower increase in glycine and
PCP
receptor binding. Furthermore, maximal glycine and
PCP
receptor binding densities were not reached until PND 28 and were lower than NMDA recognition site binding densities. The observed developmental patterns of binding to each of the receptor components of the NMDA receptor channel/complex are consistent with postnatal changes in cytoarchitecture, synaptogenesis, afferent lamination, and functional development of the hippocampus. However, the relative overexpression of NMDA recognition sites with respect to glycine and
PCP
receptors between PND 7 and 21 suggests that there is differential expression of these binding sites during development.
...
PMID:Differential ontogenic development of three receptors comprising the NMDA receptor/channel complex in the rat hippocampus. 217 75
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