Inhibition of [3H]spiperone binding to cloned human and rat D2, D3 and D4 receptors by L-745,870, clozapine and haloperidol
| Ki(nM) | Receptor Selectivity | ||||
|---|---|---|---|---|---|
| hD2 CHO | hD3 HEK | hD4 HEK | D2/D4 | D3/D4 | |
| L-745,870 | |||||
| Human | 960 | 2300 | 0.43 | 2233 | 5349 |
| (680; 1100) | (1800; 2800) | (0.28; 0.66) | |||
| Rat | 1600 | 6200 | 1.5 | 1066 | 4133 |
| (1500; 1700) | (1.4; 1.6) | ||||
| Clozapine | |||||
| Human | 74 | 200 | 10 | 7.4 | 20 |
| (65; 83) | (180; 220) | (5.8; 19) | |||
| Rat | 210 | 100 | 32 | 6.6 | 3.1 |
| (140; 310) | (92; 110) | (25; 41) | |||
| Haloperidol | |||||
| Human | 1.4 | 2 | 2.3 | 0.6 | 0.9 |
| (1.1; 1.8) | (0.95; 4.2) | (1.9; 2.9) | |||
| Rat | 1.5 | 3.8 | 13 | 0.1 | 0.3 |
| (1.1; 1.9) | (2.9; 4.9) | (6.9; 24) | |||
Competition studies were performed as described in “Methods.” Data represent mean Ki values (with low and high errors of the mean in parentheses) determined from three–eight separate experiments. Ki values were calculated from the IC50 values using the Cheng Prusoff equation (Cheng and Prusoff, 1973).