Fig. 5.

Effect of amino acid and inosine monophosphate (IMP) on duodenal HCO₃⁻ secretion in rats. Duodenal HCO₃⁻ secretion is expressed as total CO₂ output. Perfusion of l-Glu (10 mM) or IMP (0.1 mM) had a little effect on HCO₃⁻ secretion, while l-Glu coperfused with IMP synergistically augmented HCO₃⁻ secretion (A). Similar synergism was observed with perfusion of l-Asp (10 mM) (B) or l-Leu (10 mM) (D), whereas l-Ala (10 mM) increased HCO₃⁻ secretion without the synergy with IMP (C). Each data point represents mean ± SE (n = 6 rats). *P < 0.05 vs. pH 7.0 Krebs group, †P < 0.05 vs. the corresponding amino acid group.