Ascorbic acid secretion in the human stomach and the effect of gastrin

AIM To investigate the changes of gastricmucosal ascorbic acid secretion in patients withnonulcer dyspepsia and the effect of gastrin onit,and to relate any observed changes to H.pylori infection and mucosal histology.METHODS Ascorbic acid secretions in patientswere examined by collecting continuouslygastric juice for one hour after having aspiratedand discarded fasting gastric juice.Using theclearance rate(mL/min)of ascorbic acid fromblood to gastric juice represented ascorbic acidsecretion in the gastric mucosa.Ascorbic acidconcentrations in plasma and juice weremeasured by ferric reduced method.RESULTS Gastric ascorbic acid secretions inH.pylori-positive patients(1.46 mL/min,range0.27-3.78)did not significantly differ fromthose in H.pylori-negative patients(1.25 mL/min,0.47-3.14)(P>0.05).There were nosignificant differences in ascorbic acidsecretions between patients with mild(1.56 mL/min,0.50-3.30),moderate(1.34 mL/min,0.27-2.93)and severe(1.36 mL/min,0.47-3.78)inflammation(P>0.05).There were nosignificant differences in ascorbic acidsecretions between patients without activity(l.45mL/min,0.27-3.14)and with mild(1.32mL/min,0.61-2.93),moderate(1.49mL/min,0.50-3.78)and severe(1.43 mL/min,0.51-3.26)activity of chronic gastritis either(P>0.05).Ascorbic acid secretions in patientswith severe atrophy(0.56 mL/min,0.27-1.20)were markedly lower than those in patientswithout atrophy(1.51 mL/min,0.59-3.30)and with mild(1.43 mL/ min,0.53-3.78)andmoderate(1.31 mL/min,0.47-3.16)atrophy(P<0.005).There was a significant negativecorrelation between ascorbic acid secretion andseverity of atrophy(correlation coefficient=-0.43,P<0.005).After administration ofpentagastrin,ascorbic acid secretions weremarkedly elevated(from 1.39 mL/min,0.36-2.96 to 3.53mL/min,0.84-5.91)(P<0.001).CONCLUSION Ascorbic acid secretion ingastric mucosa is not affected by H.pyloriinfection.Gastric ascorbic acid secretion ismarkedly related to the severity of atrophy,whereas not related to the severity ofinflammation and activity.Gastrin may stimulategastric ascorbic acid secretion.A decreasedascorbic acid secretion may be an importantfactor in the link between atrophic gastritis andgastric carcinogenesis.