TABLE 3.
Effect of external divalents on inward single-channel conductance
| ROMK | L160A | L160G | L160G-I163M | |
|---|---|---|---|---|
| 0 Mg, 0 Ca | 46.7 ± 2 (7) | 52.0 ± 4 (9) | 38.3 ± 3 (10) | 42.8 ± 5 (5) |
| 1 mM Mg, 2 mM Ca | 33.7 ± 2 (10)* | 31.6 ± 1 (19)* | 28.9 ± 3 (4)* | — |
| % block | 28% | 39% | 25% | — |
Inward single-channel conductance (pS) was measured in the linear region of the current-voltage relation between −50 and −150 mV, with external pH = 8, acetate solutions. Conductances are in pS ± SE, with the number of oocytes in parentheses. Percent block refers to the % decrease in conductance attributable to block by external divalents = 1–(gdivalent/g).
*
External divalents produced a significant reduction in conductance for each channel type (P < 0.005). With the same pipette solution, different channel types had no significant differences in conductance (P > 0.05).