1998 Volume 77 Issue 2 Pages 169-172
We examined the effects of 4 corymine-related compounds on glycine-induced chloride current in Xenopus oocytes. Dihydrocorymine, N-demethyl-3-epi-dihydrocorymine and deformylcorymine dose-dependently decreased the glycine current with IC50 values of 34, 37 and 55 μM, respectively. The effect of these compounds on the glycine current was more potent than that of pleiocarpamine (IC50 > 1 mM). N-Demethyl-3-epi-dihydrocorymine and dihydrocorymine, at 100 μM, also decreased the γ-aminobutyric acid-induced current by 65% and 22%, respectively, whereas deformylcorymine and pleiocarpamine failed. The inhibitory action of deformylcorymine on the glycine current was noncompetitive. These results suggest that deformylcorymine is a novel specific noncompetitive glycine receptor antagonist. The structure-activity relationship of these compounds was discussed.