Figure 11.

Different ATPase inhibitors differentially affect external gluconate permeability. (A) AMP-PNP (5 mM) has a similar effect to PPi (Fig. 9 A), increasing Cl⁻ efflux and stimulating gluconate influx. In contrast, both NaN₃ (5 mM) and ADP (1 mM) reduced Cl⁻ efflux without allowing any measurable gluconate influx. (B) Mean values of P _Gluconate/P _Cl for gluconate in the extracellular solution under different conditions. The values for NaN₃ and ADP, like those for control, are maximum values (see Fig. 9 B). Mean of data from 36 patches for control and 4–5 patches under other conditions. *P _Gluconate/P _Cl is significantly greater than 0.013 (P < 0.05, one-tailed t test; see Fig. 9 B).