Table 5.
Apparent affinity (pKI′) and nH values expressed by R-α-MH and thioperamide at H3-receptors in guinea-pig cortex in buffer containing increasing concentrations of CaCl2
| Buffer | R-α-MH | Thioperamide | ||
|---|---|---|---|---|
| pKI′ | nH | pKI | nH | |
| B(0,0,0) | 9.03±0.08 | 0.54±0.04* | 8.28±0.08 | 1.04±0.28 |
| B(0.03,0,0) | 8.59±0.21 | 0.52±0.04* | 8.55±0.09 | 0.93±0.14 |
| B(0.07,0,0) | 8.45±0.07 | 0.54±0.02* | 8.46±0.08 | 0.90±0.04 |
| B(0.1,0,0) | 8.09±0.13 | 0.60±0.06* | 8.38±0.16 | 0.87±0.05 |
| B(0.2,0,0) | 7.68±0.07 | 0.68±0.03* | 8.44±0.08 | 1.14±0.13 |
| B(0.3,0,0) | 7.24±0.06 | 0.88±0.08 | 8.39±0.06 | 0.95±0.02 |
Data are the mean±s.e.m. of three experiments. The concentrations of CaCl2 used in the buffers were the same as those in the experiments described in Table 3.
*
nH significantly different from unity, P<0.05 t-test.