Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

NMDA receptors phencyclidine

Hypofunction of NMDA receptors may contribute to the endophenotype of schizophrenia. The hypothesis that hypofunction of a subpopulation of NMDA receptors contributes to the pathophysiology of schizophrenia has gained considerable support over the last decade (see Fig. 54-1). The dissociative anesthetics including phencyclidine (PCP) and ketamine when introduced clinically 40 years ago were noted to produce a syndrome that was difficult to distinguish from schizophrenia. These agents act as noncompetitive open-channel blockers of the NMDA receptor. [Pg.880]

Phencyclidine (PCP) psychosis faithfully masquerades as schizophrenia, though some say it resembles mania. PCP is discovered to block NMDA subtypes of glutamate receptors. Glycine and cycloserine, which stimulate NMDA receptors, are antipsychotic. [Pg.80]

The mechanisms of action of phencyclidine and ketamine are complex (Gorelick Balster, 1995). The drugs are non-competitive antagonists at NMDA receptors, and also bind to associated phencyclidine/sigma opioid receptors. They also have agonist actions at dopamine receptors, complex interactions with both nicotinic and muscarinic acetylcholine receptors and poorly understood interactions with noradrenergic and serotonergic systems. These multiple actions may combine to produce delirium and psychotic reactions. [Pg.188]

Glutamate systems have long been implicated in the pathophysiology of schizophrenia. Strong if circumstantial evidence comes from the psychosis associated with phencyclidine (PGP) administration PGP blocks of the ion channel the glutamate/NMDA receptor. Psychosis due to PGP and other noncompetitive NMDA antagonists includes the development of negative as well as positive symptoms and therefore is considered a better model of schizophre-... [Pg.285]

Animal research has revealed that antagonists, such as ketamine, phencyclidine, and dizocilpine [MK-801], at the NMDA receptor channel complex are clearly anxiolytic in animal models of anxiety. Because of the risk of abuse with phencyclidine-related drugs, which are thought to act at a site within the channel itself, antagonists at another site associated with the NMDA receptor channel complex—namely, those that act at the glycine-modulatory site on the NMDA receptor—are believed to have promise in the development of future anxiolytics [Hamon 1994]. [Pg.339]

Klamer D., Zhang J., Engel J. A., and Svensson L. (2005). Selective interaction of nitric oxide synthase inhibition with phencyclidine behavioural and NMDA receptor binding studies in the rat. Behav. Brain Res. 159 95-103. [Pg.257]

Figure 14.8. Sites of action of endogenous ligands and drugs that modulate the action of excitatory amino acids on the NMDA receptor. Recent evidence shows that glutamate (Glut) and possibly other excitatory amino acids released from presynaptic terminals activate the NMDA receptor site on postsynaptic membranes, resulting in the opening of the Na+/Ca++ channels. Glycine acts on a strychnine-insensitive receptor while polyamines (e.g. spermine and spermidine) also have a modulatory role. Conversely Zn++ and Mg++ and drugs like phencyclidine (PCP) block the ion channel by acting at various sites on the NMDA receptor complex or... Figure 14.8. Sites of action of endogenous ligands and drugs that modulate the action of excitatory amino acids on the NMDA receptor. Recent evidence shows that glutamate (Glut) and possibly other excitatory amino acids released from presynaptic terminals activate the NMDA receptor site on postsynaptic membranes, resulting in the opening of the Na+/Ca++ channels. Glycine acts on a strychnine-insensitive receptor while polyamines (e.g. spermine and spermidine) also have a modulatory role. Conversely Zn++ and Mg++ and drugs like phencyclidine (PCP) block the ion channel by acting at various sites on the NMDA receptor complex or...
Both phencyclidine and ketamine bind with high affinity to a number of receptors in the brain, but it is now accepted that the primary target is the sigma-PCP receptor site located in the ion channel of the NMDA excitatory amino acid receptor complex. The precise function of this receptor in the brain is still the subject of debate. It is now known that there are two distinct sigma receptor sites in the mammalian brain (ctj and a2) which are not associated with the NMDA receptor complex. Haloperidol and the atypical neuroleptic remoxipride bind with high affinity to such sites, and it has been postulated that some typical and atypical neuroleptics may owe some of their pharmacological effects to their action on such receptors. [Pg.409]

Considerable attention is now being paid to the way in which phencyclidine and ketamine block the ion channel controlled by the NMDA receptor. This prevents the movement of calcium ions in particular into the cell which, in the case of the NMDA receptors situated in the hippocampus, inhibits long-term potentiation and thereby blocks memory... [Pg.409]


See other pages where NMDA receptors phencyclidine is mentioned: [Pg.634]    [Pg.312]    [Pg.634]    [Pg.312]    [Pg.660]    [Pg.1046]    [Pg.282]    [Pg.215]    [Pg.217]    [Pg.367]    [Pg.384]    [Pg.420]    [Pg.5]    [Pg.95]    [Pg.163]    [Pg.21]    [Pg.276]    [Pg.278]    [Pg.80]    [Pg.155]    [Pg.265]    [Pg.59]    [Pg.44]    [Pg.23]    [Pg.117]    [Pg.553]    [Pg.626]    [Pg.633]    [Pg.722]    [Pg.241]    [Pg.61]    [Pg.186]    [Pg.242]    [Pg.249]    [Pg.140]    [Pg.505]    [Pg.659]    [Pg.89]    [Pg.59]    [Pg.278]    [Pg.355]    [Pg.355]    [Pg.373]    [Pg.452]   
See also in sourсe #XX -- [ Pg.409 ]




SEARCH



NMDA

NMDA phencyclidine

NMDA receptors

Phencyclidine

© 2024 chempedia.info