TABLE 1

Comparison between polyamine derivatives and memantine in NMDA channel block and cell toxicity Experiments were performed as described under Materials and Methods. Cell toxicity data for memantine are from Masuko et al. (2007b). The IC₅₀ (50% inhibition of mitochondrial enzyme activities) value of memantine was 146 μ M on the alamar blue assay, and the LC₅₀ (50% lethal concentration) value of memantine was 141 μ M on the trypan blue assay.

	NMDA Channel Block								Cell Toxicity
	NR1/NR2A		NR1/NR2B		NR1/NR2C		NR1/NR2D		Alamar Blue	Trypan Blue
	IC₅₀	n_H	IC₅₀	n_H	IC₅₀	n_H	IC₅₀	n_H	IC₅₀	IC₅₀
	μM		μM		μM		μM		μM
TsSPM	0.37	1.0	0.45	0.8	43	1.1	14	1.0	337	283
TsSPMG	0.36	0.9	0.36	0.8	21	1.1	13	1.3	2640	2510
TsHSPM	0.093	0.7	0.16	0.7	13	1.1	15	0.8	1850	1900
TsHSPMG	0.011	0.7	0.029	0.8	2.9	1.0	3.1	0.8	>3000	>3000
DnSPM	0.31	0.8	0.33	0.8	33	1.2	30	1.0	30	39
Memantine	0.88	0.8	0.52	0.9	0.59	0.7	0.57	0.7	146	141