|
V
max
|
K
m
| Vmax/Km |
---|
(fmol/min/mg total protein) | (μM) | (μL/min/mg total protein) |
---|
WT | TG | WT | TG | WT | TG |
---|
3 months | 958 ± 55 | 1166 ± 88 | 0.076 ± 0.022 | 0.069 ± 0.029 | 12.6 ± 2.5 | 16.8 ± 3.1 |
6 months | 1060 ± 76 | 1134 ± 72 | 0.078 ± 0.028 | 0.086 ± 0.027 | 13.6 ± 2.7 | 13.1 ± 2.6 |
12 months | 1112 ± 89 | 1106 ± 83 | 0.094 ± 0.036 | 0.131 ± 0.043 | 11.8 ± 2.5 | 8.4 ± 2.0 |
20 months | 1182 ± 93 | 792 ± 74* | 0.099 ± 0.037 | 0.114 ± 0.048 | 11.9 ± 2.5 | 7.0 ± 1.6 |
- Values are reported as the mean ± SEM of 3–4 independent experiments, conducted on freshly prepared membranes from the neocortex of aging wild-type (WT) and APPswe/PS1dE9 littermate transgenic (TG) mice. The apparent maximal velocity rate (Vmax) for the uptake of [3H]5-HT was reduced in 20-month-old TG vs. WT animals, without a change in the apparent Michaelis constant (Km). By one-way ANOVA, there was a modest, age-dependent reduction in the efficiency (Vmax/Km) of SERT in APPswe/PS1dE9 mice, which did not reach between-group significance by Bonferroni post hoc tests. *p < 0.05 vs. age-matched WT, two-way ANOVA followed by Bonferroni posttests