The effect of bicarbonate on secretagogue stimulated zymogen activation is decreased by PKA inhibition using H89.

Acini were treated with or without the PKA inhibitor H89 [10 µM] for 30 min prior to changing media and replacing it with either bicarbonate [25 mM] at a constant flow of air/CO₂ (95/5%) or without the addition of bicarbonate under room air conditions. H89 was added back to the appropriate wells. Secretagogue (CER 100 nM or CARB 1 mM) was added immediately after media change to the appropriate wells and acini incubated for 1 hour. Acini were collected and assayed for trypsinogen activation (A,D), chymotrypsinogen activation (B,E) and amylase secretion (C,F). #p<0.05 vs. corresponding secretagogue alone, *p<0.05 vs. corresponding secretagogue/bicarbonate treatment (n≥5).