Table 3

Effect of spermidine and MgCl₂ on the inhibition of [³H]ifenprodil binding by ifenprodil

Compound	Ifenprodil IC₅₀ μM (95% CI)	N
Control	0.050	8
	(0.041–0.061)
10 μM spermidine	0.117^3-150	7
	(0.095–0.145)
100 μM spermidine	0.536^3-150	5
	(0.384–0.748)
100 μM MgCl₂	0.076	3
	(0.062–0.094)
1000 μM MgCl₂	0.250^3-150	8
	(0.172–0.363)
10 μM spermidine ⁺ 1000 μM MgCl₂	0.241^3-150 ^{,^3-151} (0.145–0.402)	3

[³H]Ifenprodil binding was carried out in the presence of 100 μM trifluoroperazine as described under Experimental Procedures. The data are the geometric mean and the 95% CI fromN independent experiments. Binding was inhibited >80% in the presence of either 1 mM spermidine or 10 mM MgCl₂.

↵3-150 p < 0.001 compared to control;
↵3-151 p > 0.05 compared to 1000 μM MgCl₂. ANOVA with Bonferroni multiple comparisons test.