Receptors for the excitatory amino acids in the mammalian central nervous system

摘要: On the basis largely of neuropharmacological analysis, three different receptors mediating neuronal excitation can be identified. The first is activated by quisqualate and other "flexible" molecules including L-glutamate appears to bind its ligands in a folded configuration. second excited NMDA has more extended conformation, spacing between amino omega-carboxylate groups being determinant specificity. third type accepts kainate possess reactive site for unsaturated side chain which essential operation this receptor. All classes appear implicated synaptic events [although some at least are certainly extra-synaptic (Watkins et al., 1981)] each activate ionophores membranes. Of endogenous acids may function as transmitters, L-cysteate seem react preferentially with (McLennan Lodge, 1979), while L-aspartate mixed agonist capable reaction both types. Whether folate physiological role involving unknown; same true any action possessed quinolinate. fact that there acid excitants pharmacologically distinct from those reacting best known suggests one class receptor also exist, but no further information available present time. Other sites active acidic identifiable neurochemically membrane preparations derived tissues central nervous system. Kinetic studies analysis inhibition sodium-independent binding indicate accept glutamate, others aspartate binds kainate. However, does not correspond completely excitatory receptor, sites. It difficult conclude then these fully identified receptors. Finally, number systems their patterns activity again distinct, presumably mediate uptake acids.(ABSTRACT TRUNCATED AT 400 WORDS)