TABLE 2.
Binding constants for CX546 in different regions of rat brain
Binding to brain membranes was measured at room temperature for the eight indicated brain regions (n = 3). A constant concentration of [3H]fluorowillardiine (20 nM) was used with addition of 0 to 6 mM CX546, as described in Fig. 4. The data were transformed and fitted with a sigmoidal curve to determine Emax (expressed as percentage increase from control) and the potency of CX546 (EC50). ″Ratio″ indicates the ratio ″pup″/″adult″
| fr-ctx | par-ctx | Striatum | Hippocampus | Thalamus | Hypothalamus | Cerebellum | Brainstem | |
|---|---|---|---|---|---|---|---|---|
| Emax(%) | ||||||||
| Adults | 114 ± 5 | 104 ± 9 | 87 ± 4 | 189 ± 5 | 68 ± 6 | 80 ± 12 | 189 ± 1 | 91 ± 8 |
| Pups | 71 ± 2 | 69 ± 7 | 81 ± 5 | 146 ± 9 | 59 ± 2 | 69 ± 7 | 84 ± 6 | 86 ± 3 |
| Ratio | 0.62 | 0.66 | 0.93 | 0.77 | 0.87 | 0.86 | 0.44 | 0.95 |
| EC50(mM) | ||||||||
| Adults | 1.64 ± 0.1 | 1.54 ± 0.4 | 1.36 ± 0.2 | 4.21 ± 0.5 | 1.39 ± 0.3 | 1.71 ± 0.8 | 1.98 ± 0.1 | 2.58 ± 1.1 |
| Pups | 1.58 ± 0.1 | 1.59 ± 0.2 | 1.97 ± 0.5 | 3.16 ± 0.5 | 0.95 ± 0.3 | 1.69 ± 0.1 | 1.33 ± 0.2 | 1.32 ± 0.3 |
| Ratio | 0.96 | 1.03 | 1.45 | 0.75 | 0.68 | 0.99 | 0.67 | 0.51 |
fr-ctx, frontal cortex; par-ctx, parietal cortex.