Rat Liver | Rat Kidney | |||||
---|---|---|---|---|---|---|
Hill-slope | −logKi | Hill-slope | −logKi high | −logKi low | % High-affinity sites | |
Tamsulosin | 1.01 ± 0.07 | 9.38 ± 0.08 | 0.52 ± 0.07 | 10.53 ± 0.15 | 8.64 ± 0.20 | 45 ± 7 |
M1 | 0.88 ± 0.04 | 8.66 ± 0.05 | 0.55 ± 0.03 | 9.86 ± 0.21 | 8.06 ± 0.15 | 47 ± 7 |
M2 | 1.03 ± 0.06 | 8.03 ± 0.02 | 0.39 ± 0.10 | 9.63 ± 0.54 | 7.39 ± 0.22 | 36 ± 2 |
M3 | 1.10 ± 0.09 | 8.15 ± 0.02 | 0.55 ± 0.02 | 9.34 ± 0.21 | 7.62 ± 0.14 | 38 ± 3 |
M4 | 0.90 ± 0.07 | 9.45 ± 0.03 | 0.53 ± 0.04 | 10.62 ± 0.09 | 8.84 ± 0.02 | 45 ± 5 |
5-Methylurapidil | 0.92 ± 0.10 | 6.28 ± 0.39 | 0.54 ± 0.03 | 8.11 ± 0.11 | 6.32 ± 0.05 | 50 ± 4 |
(+)-Niguldipine | 1.00 ± 0.05 | 6.90 ± 0.10 | 0.39 ± 0.02 | 9.23 ± 0.05 | 6.87 ± 0.03 | 47 ± 1 |
WB 4101 | 1.10 ± 0.05 | 8.15 ± 0.08 | 0.69 ± 0.01 | 9.54 ± 0.08 | 8.18 ± 0.07 | 48 ± 9 |
Data are the means ± S.E.M. of three to five experiments. Hill-slopes for the rat kidney are derived from a monophasic fit, whereas −log K i high, and −logK i low and percentage of high-affinity sites in this tissue were estimated from a biphasic fit. In the rat kidney, the biphasic fit was significantly better than the monophasic fit (P < .05) as judged by an F test. A graphical representation of the data is shown in figures 1 and 2. Data for 5-methylurapidil, (+)-niguldipine and WB 4101 generated in our laboratory with identical methods are taken from (Michel et al., 1993, 1996;Büscher et al., 1996; Chess-Williams et al., 1996) and are shown for reference purposes.