Fig. 9. Relative mRNA expression as determined by real-time PCR for (A) Na⁺/HCO ^–₃ cotransporter (NBC), (B) V-type H⁺-ATPase and (C) lungfish carbonic anhydrase b isoform (CAb) in gill and kidney tissue sampled from lungfish infused with saline (control), acid (3 mmol kg^–1 NH₄Cl) or base (3 mmol kg^–1 NaHCO₃) for 1 h and sampled 4 h or 8 h post-infusion (control fish were sampled only at 8 h). Values are means ± 1 s.e.m.; N=3 or 4. No statistically significant differences in the expression of a gene within a tissue were detected as a result of acid or base infusion (one-way ANOVA, P>0.05 in all cases).