Abstract
1. Ifenprodil is a selective, atypical non-competitive antagonist of NMDA receptors that contain the NR2B subunit with an undefined mechanism of action. Ifenprodil is neuroprotective in in vivo models of cerebral ischaemia but lacks many of the undesirable side-effects associated with NMDA antagonist. 2. Using whole-cell voltage-clamp recordings, we have studied the mechanism of inhibition of NMDA-evoked currents by ifenprodil in rat cultured cortical neurones in the presence of saturating concentrations of glycine. 3. Ifenprodil antagonized NMDA receptors in an activity-dependent manner, whilst also increasing the receptor affinity for glutamate recognition-site agonists. Ifenprodil inhibition curves against 10 and 100 microM NMDA-evoked currents yielded IC50 values of 0.88 and 0.17 microM, respectively. Thus, the apparent affinity of ifenprodil for the NMDA receptor is increased in an NMDA concentration-dependent manner. 4. Currents evoked by 0.3 and 1 microM NMDA were potentiated to approximately 200% of control levels in the presence of 3 microM ifenprodil. Thus, with increasing concentration of NMDA the effect of ifenprodil on NMDA-evoked currents changed from one of potentiation to one of increasing inhibition. 5. These results are predicted by a reaction scheme in which ifenprodil exhibits a 39- and 50-fold higher affinity for the agonist-bound activated and desensitized states of the NMDA receptor, respectively, relative to the resting, agonist-unbound state. Furthermore, ifenprodil binding to the NMDA receptor results in a 6-fold higher affinity for glutamate site agonists. 6. This represents a novel mechanism of NMDA receptor antagonism that, together with the subunit selectivity, probably contributes to the attractive neuropharmacological profile of this and related compounds.
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Selected References
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- Benveniste M., Clements J., Vyklický L., Jr, Mayer M. L. A kinetic analysis of the modulation of N-methyl-D-aspartic acid receptors by glycine in mouse cultured hippocampal neurones. J Physiol. 1990 Sep;428:333–357. doi: 10.1113/jphysiol.1990.sp018215. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Benveniste M., Mayer M. L. Kinetic analysis of antagonist action at N-methyl-D-aspartic acid receptors. Two binding sites each for glutamate and glycine. Biophys J. 1991 Mar;59(3):560–573. doi: 10.1016/S0006-3495(91)82272-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Benveniste M., Mayer M. L. Multiple effects of spermine on N-methyl-D-aspartic acid receptor responses of rat cultured hippocampal neurones. J Physiol. 1993 May;464:131–163. doi: 10.1113/jphysiol.1993.sp019627. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Benveniste M., Mayer M. L. Trapping of glutamate and glycine during open channel block of rat hippocampal neuron NMDA receptors by 9-aminoacridine. J Physiol. 1995 Mar 1;483(Pt 2):367–384. doi: 10.1113/jphysiol.1995.sp020591. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carter C. J., Lloyd K. G., Zivkovic B., Scatton B. Ifenprodil and SL 82.0715 as cerebral antiischemic agents. III. Evidence for antagonistic effects at the polyamine modulatory site within the N-methyl-D-aspartate receptor complex. J Pharmacol Exp Ther. 1990 May;253(2):475–482. [PubMed] [Google Scholar]
- Carter C., Benavides J., Legendre P., Vincent J. D., Noel F., Thuret F., Lloyd K. G., Arbilla S., Zivkovic B., MacKenzie E. T. Ifenprodil and SL 82.0715 as cerebral anti-ischemic agents. II. Evidence for N-methyl-D-aspartate receptor antagonist properties. J Pharmacol Exp Ther. 1988 Dec;247(3):1222–1232. [PubMed] [Google Scholar]
- Clements J. D., Westbrook G. L. Activation kinetics reveal the number of glutamate and glycine binding sites on the N-methyl-D-aspartate receptor. Neuron. 1991 Oct;7(4):605–613. doi: 10.1016/0896-6273(91)90373-8. [DOI] [PubMed] [Google Scholar]
- Colquhoun D., Hawkes A. G. Desensitization of N-methyl-D-aspartate receptors: a problem of interpretation. Proc Natl Acad Sci U S A. 1995 Oct 24;92(22):10327–10329. doi: 10.1073/pnas.92.22.10327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gallagher M. J., Huang H., Pritchett D. B., Lynch D. R. Interactions between ifenprodil and the NR2B subunit of the N-methyl-D-aspartate receptor. J Biol Chem. 1996 Apr 19;271(16):9603–9611. doi: 10.1074/jbc.271.16.9603. [DOI] [PubMed] [Google Scholar]
- Gotti B., Duverger D., Bertin J., Carter C., Dupont R., Frost J., Gaudilliere B., MacKenzie E. T., Rousseau J., Scatton B. Ifenprodil and SL 82.0715 as cerebral anti-ischemic agents. I. Evidence for efficacy in models of focal cerebral ischemia. J Pharmacol Exp Ther. 1988 Dec;247(3):1211–1221. [PubMed] [Google Scholar]
- Gozlan H., Ben-Ari Y. NMDA receptor redox sites: are they targets for selective neuronal protection? Trends Pharmacol Sci. 1995 Nov;16(11):368–374. doi: 10.1016/s0165-6147(00)89077-x. [DOI] [PubMed] [Google Scholar]
- Graham D., Darles G., Langer S. Z. The neuroprotective properties of ifenprodil, a novel NMDA receptor antagonist, in neuronal cell culture toxicity studies. Eur J Pharmacol. 1992 Aug 3;226(4):373–376. doi: 10.1016/0922-4106(92)90056-2. [DOI] [PubMed] [Google Scholar]
- Hille B. Local anesthetics: hydrophilic and hydrophobic pathways for the drug-receptor reaction. J Gen Physiol. 1977 Apr;69(4):497–515. doi: 10.1085/jgp.69.4.497. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jackson A., Sanger D. J. Is the discriminative stimulus produced by phencyclidine due to an interaction with N-methyl-D-aspartate receptors? Psychopharmacology (Berl) 1988;96(1):87–92. doi: 10.1007/BF02431538. [DOI] [PubMed] [Google Scholar]
- Johnson J. W., Ascher P. Glycine potentiates the NMDA response in cultured mouse brain neurons. Nature. 1987 Feb 5;325(6104):529–531. doi: 10.1038/325529a0. [DOI] [PubMed] [Google Scholar]
- Kleckner N. W., Pallotta B. S. Burst kinetics of single NMDA receptor currents in cell-attached patches from rat brain cortical neurons in culture. J Physiol. 1995 Jul 15;486(Pt 2):411–426. doi: 10.1113/jphysiol.1995.sp020822. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kutsuwada T., Kashiwabuchi N., Mori H., Sakimura K., Kushiya E., Araki K., Meguro H., Masaki H., Kumanishi T., Arakawa M. Molecular diversity of the NMDA receptor channel. Nature. 1992 Jul 2;358(6381):36–41. doi: 10.1038/358036a0. [DOI] [PubMed] [Google Scholar]
- Laurie D. J., Seeburg P. H. Regional and developmental heterogeneity in splicing of the rat brain NMDAR1 mRNA. J Neurosci. 1994 May;14(5 Pt 2):3180–3194. doi: 10.1523/JNEUROSCI.14-05-03180.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Legendre P., Rosenmund C., Westbrook G. L. Inactivation of NMDA channels in cultured hippocampal neurons by intracellular calcium. J Neurosci. 1993 Feb;13(2):674–684. doi: 10.1523/JNEUROSCI.13-02-00674.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Legendre P., Westbrook G. L. Ifenprodil blocks N-methyl-D-aspartate receptors by a two-component mechanism. Mol Pharmacol. 1991 Aug;40(2):289–298. [PubMed] [Google Scholar]
- Lester R. A., Clements J. D., Westbrook G. L., Jahr C. E. Channel kinetics determine the time course of NMDA receptor-mediated synaptic currents. Nature. 1990 Aug 9;346(6284):565–567. doi: 10.1038/346565a0. [DOI] [PubMed] [Google Scholar]
- Lester R. A., Jahr C. E. NMDA channel behavior depends on agonist affinity. J Neurosci. 1992 Feb;12(2):635–643. doi: 10.1523/JNEUROSCI.12-02-00635.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lester R. A., Tong G., Jahr C. E. Interactions between the glycine and glutamate binding sites of the NMDA receptor. J Neurosci. 1993 Mar;13(3):1088–1096. doi: 10.1523/JNEUROSCI.13-03-01088.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lin F., Stevens C. F. Both open and closed NMDA receptor channels desensitize. J Neurosci. 1994 Apr;14(4):2153–2160. doi: 10.1523/JNEUROSCI.14-04-02153.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mayer M. L., Westbrook G. L., Guthrie P. B. Voltage-dependent block by Mg2+ of NMDA responses in spinal cord neurones. Nature. 1984 May 17;309(5965):261–263. doi: 10.1038/309261a0. [DOI] [PubMed] [Google Scholar]
- McBain C. J., Mayer M. L. N-methyl-D-aspartic acid receptor structure and function. Physiol Rev. 1994 Jul;74(3):723–760. doi: 10.1152/physrev.1994.74.3.723. [DOI] [PubMed] [Google Scholar]
- Monyer H., Sprengel R., Schoepfer R., Herb A., Higuchi M., Lomeli H., Burnashev N., Sakmann B., Seeburg P. H. Heteromeric NMDA receptors: molecular and functional distinction of subtypes. Science. 1992 May 22;256(5060):1217–1221. doi: 10.1126/science.256.5060.1217. [DOI] [PubMed] [Google Scholar]
- Möckel V., Fischer G. Vulnerability to excitotoxic stimuli of cultured rat hippocampal neurons containing the calcium-binding proteins calretinin and calbindin D28K. Brain Res. 1994 Jun 13;648(1):109–120. doi: 10.1016/0006-8993(94)91911-9. [DOI] [PubMed] [Google Scholar]
- Nowak L., Bregestovski P., Ascher P., Herbet A., Prochiantz A. Magnesium gates glutamate-activated channels in mouse central neurones. Nature. 1984 Feb 2;307(5950):462–465. doi: 10.1038/307462a0. [DOI] [PubMed] [Google Scholar]
- Paoletti P., Neyton J., Ascher P. Glycine-independent and subunit-specific potentiation of NMDA responses by extracellular Mg2+. Neuron. 1995 Nov;15(5):1109–1120. doi: 10.1016/0896-6273(95)90099-3. [DOI] [PubMed] [Google Scholar]
- Patneau D. K., Mayer M. L. Structure-activity relationships for amino acid transmitter candidates acting at N-methyl-D-aspartate and quisqualate receptors. J Neurosci. 1990 Jul;10(7):2385–2399. doi: 10.1523/JNEUROSCI.10-07-02385.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Peters S., Koh J., Choi D. W. Zinc selectively blocks the action of N-methyl-D-aspartate on cortical neurons. Science. 1987 May 1;236(4801):589–593. doi: 10.1126/science.2883728. [DOI] [PubMed] [Google Scholar]
- Priestley T., Ochu E., Kemp J. A. Subtypes of NMDA receptor in neurones cultured from rat brain. Neuroreport. 1994 Sep 8;5(14):1763–1765. doi: 10.1097/00001756-199409080-00019. [DOI] [PubMed] [Google Scholar]
- Ransom R. W. Polyamine and ifenprodil interactions with the NMDA receptor's glycine site. Eur J Pharmacol. 1991 Sep 12;208(1):67–71. doi: 10.1016/0922-4106(91)90052-j. [DOI] [PubMed] [Google Scholar]
- Reynolds I. J., Miller R. J. Ifenprodil is a novel type of N-methyl-D-aspartate receptor antagonist: interaction with polyamines. Mol Pharmacol. 1989 Nov;36(5):758–765. [PubMed] [Google Scholar]
- Sheng M., Cummings J., Roldan L. A., Jan Y. N., Jan L. Y. Changing subunit composition of heteromeric NMDA receptors during development of rat cortex. Nature. 1994 Mar 10;368(6467):144–147. doi: 10.1038/368144a0. [DOI] [PubMed] [Google Scholar]
- Traynelis S. F., Hartley M., Heinemann S. F. Control of proton sensitivity of the NMDA receptor by RNA splicing and polyamines. Science. 1995 May 12;268(5212):873–876. doi: 10.1126/science.7754371. [DOI] [PubMed] [Google Scholar]
- Williams K. Ifenprodil discriminates subtypes of the N-methyl-D-aspartate receptor: selectivity and mechanisms at recombinant heteromeric receptors. Mol Pharmacol. 1993 Oct;44(4):851–859. [PubMed] [Google Scholar]
- Williams K., Russell S. L., Shen Y. M., Molinoff P. B. Developmental switch in the expression of NMDA receptors occurs in vivo and in vitro. Neuron. 1993 Feb;10(2):267–278. doi: 10.1016/0896-6273(93)90317-k. [DOI] [PubMed] [Google Scholar]
