Fig. 5.

Inhibition of HCO₃⁻ absorption by bath LPS does not involve basolateral Na⁺/H⁺ exchange. MTALs from rats were studied with 10 μM amiloride in the bath (A) or in a Na⁺-free bath (B), conditions that inhibit basolateral Na⁺/H⁺ exchange (28, 34, 77, 78). LPS (500 ng/ml) was then added to and removed from the bath solution. In B, Na⁺ in the bath was replaced with NMDG⁺; the lumen was perfused with control solution containing 146 mM Na⁺ (28, 77). J_HCO3⁻, data points, lines, and P values are as in Fig. 1. Mean values are given in results.