Effects of anaesthetic agents on gastrin-stimulated and histamine-stimulated gastric acid secretion in the totally isolated vascularly perfused rat stomach.

BACKGROUND

Anaesthetic agents affect gastric acid secretion, but the mechanisms behind this action have not been fully evaluated. The enterochromaffin-like (ECL) cell plays a key role in the regulation of gastric acid secretion, and anaesthetic agents have recently been described as inhibiting histamine release from the ECL cell. The present study examines the effect of anaesthetic agents on the ECL cell and on parietal cell functions.

METHODS

Different concentrations of urethane, pentobarbital and a mixture of fluanisone/fantanyl/midazolam (FFM) were examined for the effect on gastrin-stimulated histamine release and acid secretion and on histamine-stimulated acid secretion in the totally isolated vascularly perfused rat stomach. The luminal acid output and histamine concentrations in venous effluents were measured by titration and radioimmunoassay, respectively.

RESULTS

Pentobarbital caused an inhibition on both histamine release and acid output in gastrin-stimulated stomachs in a concentration-dependent way. The mixture of FFM at higher concentrations inhibited histamine release from the ECL cell and luminal H+ output in gastrin-stimulated acid secretion. Urethane exerted a slight inhibitory effect on histamine release only at the lowest concentration. Pentobarbital also reduced histamine-stimulated gastric acid secretion, while the mixture of FFM did not.

CONCLUSIONS

pentobarbital inhibits acid secretion both by reducing ECL cell histamine release and parietal cell H+ secretion, whereas FFM inhibits acid secretion by interaction with the ECL cell only. Urethane also had a slight inhibitory effect on the ECL cell histamine release at the lowest concentration.