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Irreversible Agonist
An irreversible agonist is a type of agonist that binds permanently to a receptor in such a manner that the receptor is permanently activated. It is distinct from a mere (reversible) agonist in that the association of an agonist to a receptor is reversible, whereas the binding of an irreversible agonist to a receptor is, at least in theory, irreversible. Oxymorphazone is an example of an irreversible agonist. In practice, the distinction may be more a matter of degree, in which the binding affinity of an irreversible agonist is some orders of magnitude greater than that of an agonist. Examples * Oxymorphazone * Metaphit See also * Agonist * Irreversible antagonist An irreversible antagonist is a type of antagonist that binds permanently to a receptor, either by forming a covalent bond to the active site, or alternatively just by binding so tightly that the rate of dissociation is effectively zero at rele ... * Irreversible enzyme inhibitor References Receptor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology From the Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive Types of agonists can be activated by either endogenous agonists (such as |
Oxymorphazone
Oxymorphazone is an opioid analgesic drug related to oxymorphone. Oxymorphazone is a potent and long acting μ-opioid agonist which binds irreversibly to the receptor, forming a covalent bond which prevents it from detaching once bound. This gives it an unusual pharmacological profile, and while oxymorphazone is only around half the potency of oxymorphone, with higher doses the analgesic effect becomes extremely long lasting, with a duration of up to 48 hours. However, tolerance to analgesia develops rapidly with repeated doses, as chronically activated opioid receptors are rapidly internalised by β-arrestins, similar to the results of non-covalent binding by repeated doses of agonists with extremely high binding affinity such as lofentanil. See also * Chlornaltrexamine, an irreversible mixed μ-opioid agonist-antagonist * Chloroxymorphamine, another irreversible μ-opioid full agonist * Naloxazone Naloxazone is an irreversible μ-opioid receptor antagonist which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaphit
Metaphit (1- -(3-Isothiocyanato)phenylyclohexylpiperidine) is a research chemical that acts as an acylator of NMDARAn, sigma and DAT binding sites in the CNS. It is the ''m''-isothiocyanate derivative of phencyclidine (PCP) and binds irreversibly (forming a covalent bond) to the PCP binding site on the NMDA receptor complex. However, later studies suggest the functionality of metaphit is mediated by sites not involved in PCP-induced passive avoidance deficit, and not related to the NMDA receptor complex. Metaphit was also shown to prevent d-amphetamine induced hyperactivity, while significantly depleting dopamine content in the nucleus accumbens. Metaphit was the first acylating ligand used to study the cocaine receptor. It is a structural isomer of the similar research compound fourphit, as it and metaphit both are isothiocyanate substituted derivatives of an analogous scaffold shared with PCP. References {{Navboxes , title = Pharmacodynamics Pharmacodynamics (PD) is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology From the Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive Types of agonists can be activated by either endogenous agonists (such as |
Irreversible Antagonist
An irreversible antagonist is a type of antagonist that binds permanently to a receptor, either by forming a covalent bond to the active site, or alternatively just by binding so tightly that the rate of dissociation is effectively zero at relevant time scales. This permanently deactivates the receptor and is usually followed by rapid internalisation and recycling of the non-functional receptor protein. Irreversible enzyme inhibitors that act similarly are clinically used and include drugs such as aspirin, omeprazole and monoamine oxidase inhibitors.Rang and Dale's Pharmacology. (6th edition, 2007). p19. Examples * Naloxazone * Phenoxybenzamine See also * Irreversible agonist An irreversible agonist is a type of agonist that binds permanently to a receptor in such a manner that the receptor is permanently activated. It is distinct from a mere (reversible) agonist in that the association of an agonist to a receptor is ... * Irreversible enzyme inhibitor References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irreversible Inhibition
An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a specific chemical reaction by binding the substrate to its active site, a specialized area on the enzyme that accelerates the most difficult step of the reaction. An enzyme inhibitor stops ("inhibits") this process, either by binding to the enzyme's active site (thus preventing the substrate itself from binding) or by binding to another site on the enzyme such that the enzyme's catalysis of the reaction is blocked. Enzyme inhibitors may bind reversibly or irreversibly. Irreversible inhibitors form a chemical bond with the enzyme such that the enzyme is inhibited until the chemical bond is broken. By contrast, reversible inhibitors bind non-covalently and may spontaneously leave the enzyme, allowing the enzyme to resume its function. Rever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Agonists
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology From the Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive Types of agonists can be activated by either endogenous agonists (such as |
