Fig. 3

Measurement of total GAG and IDS activity in the brain. In all groups, the brain tissues of untreated KO mice showed significantly increased GAG concentrations compared with those of WT mice (p < 0.05). In group A, the IDS KO mice treated with 10 mg/kg IDS had significantly reduced brain GAG levels compared with the untreated IDS KO mice (p < 0.05) (a). In group B, compared with the untreated KO mice group, all treated groups showed significantly decreased brain GAG concentrations (p < 0.05) (b). In group C, no significant changes in brain GAG levels were found in any of the treated groups at any dose when treatment was started later (at 8 months) (c). IDS activity was measured in homogenates from the brains of treated mice (10 weeks of age) at 4 h after a single injection with doses of 1, 5, or 10 mg/kg (each dose, n = 3) (d). Brain IDS activities increased in parallel with the concentrations of IDS injected in the IDS KO mice. The data are the mean ± standard deviations. p < 0.05 versus untreated IDS KO control (ANOVA test). (***p < 0.001, **p < 0.01)