[Analysis of 3H-kainic acid binding to brain membranes in rats and frogs].
It has been shown that H3-kainic acid (3H-KA) specifically binds with membrane preparations from various parts of rat brain or whole frog brain. The saturation isotherms of 3H-KA binding revealed the presence of two sites with a high and low affinity. An exception was for rat cerebellum where Scatchard analysis showed but one low affinity site. The density of 3H-KA binding sites in frog brain was 5 to 10 times higher than in rat brain. Among the drugs studied, KA itself, L-glutamate and folic acid were the most potent inhibitors of specific binding. Methyltetrahydrofolate, quinolinic acid, kynurenine, GABA, taurine, L-aspartate were ineffective in this respect. The kinetic analysis of the binding data in the presence or absence of L-glutamate and folic acid showed, however, that these drugs inhibited 3H-KA binding in a noncompetitive manner. In the light of these findings L-glutamate or folate cannot be considered as endogenous ligands for hypothetic "kainate receptors".
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D007608:Kainic Acid / Q000378:metabolism*; D007700:Kinetics; D008024:Ligands; D008297:Male; D011759:Pyrrolidines / Q000378:metabolism*; D011898:Ranidae; D051381:Rats; D014316:Tritium
D008024:Ligands; D011759:Pyrrolidines; D014316:Tritium; D007608:Kainic Acid
Analiz sviazyvaniia 3H-kainovoĭ kisloty s membranami mozga krysy i liagushki.