Table 1.
Concentration response profiles for HOE694 on Na+–H+ exchange activities in A6/C1 and A6/NHE3 cells
| Cell type | NHE activity | [HOE694] | |||
|---|---|---|---|---|---|
| 5 ± 10−5 M | 7.5 ± 10−5 M | 10−4 M | 10−3 M | ||
| A6/C1 | Basolateral | 57.6 ± 4.3*‡§(4) | 69.0 ± 6.2*‡§(3) | 96.8 ± 3.2*‡§(3) | — |
| A6/NHE3, clone 6s | Apical | 28.0 ± 3.7*†(5) | 41.3 ± 4.5*†(3) | 48.7 ± 4.3*†(4) | 94.5 ± 3.3*(4) |
| Basolateral | 59.7 ± 5.3*(4) | 64.9 ± 1.8*(4) | 85.5 ± 1.8*(3) | — | |
| A6/NHE3, clone 9s | Apical | 33.4 ± 2.5*†(5) | 39.7 ± 6.2*†(4) | 46.1 ± 5.7*†(7) | — |
| Basolateral | 57.8 ± 4.8*(4) | 74.1 ± 5.7*(5) | 89.8 ± 4.6*(3) | — | |
Values are the mean ± s.e.m. of the NHE activity inhibition (%) with the number of experiments performed under identical conditions (n) given in parentheses. Confluent cell cultures of A6/C1 and A6/NHE3 cells were examined for Na+-dependent recovery of pHi from an acid load as described in Fig. 3. Effects of HOE694 were studied after repetitive acidification of cell cultures to control acid pHi values. Data represent the initial decrease of pHi recovery rates resulting from a 2 min exposure of either the apical or basolateral cell surface to indicated concentrations of HOE694.
Significant vs. control
significant vs. basolateral effect of HOE694
significant compared with apical NHE inhibition in clone 6s
significant compared with apical NHE inhibition in clone 9s.