Simultaneous Measurement of Gastric Acid and Bicarbonate Secretion in Man

Abstract

Experiments were performed to validate the computerized pH/Pco₂ technique for measurement of HCO₃ secretion at a physiologic pH in the human stomach. In bench-side experiments the system detected 103 ± 2% (mean ± SE, n = 66) of boluses or infusions of NaHCO₃. The standard curve was linear in the physiologic concentration range, and in the pH interval from 1.8 to 6.9 the recovery rate of added HCO₃ was independent of the pH of the aspirate. In vivo the recovery rate of an exogenous NaHCO₃ infusion (240 umol/15 min) was 95 ± 5% (n = 9), and there was no significant correlation between basal gastric pH and recovery rate. The results support that our computerized gastric perfusion method can be used for quantification of gastric bicarbonate secretion also at a physiologic acid pH.

Key Words:

• Acid secretion
• carbon dioxide
• gastric bicarbonate secretion
• gastric mucosa
• HCO₃