Hypergastrinaemia: a new mechanism.

The mechanism by which lack of gastric acid causes hypergastrinaemia was investigated in seven patients with pernicious anaemia. Perfusion of gastric juice from the fasting patients (adjusted to pH 7.0) into the stomachs of conscious rats caused a significant rise in plasma gastrin (median 14 [range 2-20] pmol/l to 27 [12-65] pmol/l; p less than 0.01), whereas perfusion of bicarbonate buffer (18 [13-23] pmol/l to 20 [9-25] pmol/l) or gastric juice from a duodenal ulcer patient (also pH 7.0; 13 [3-30] pmol/l to 17 [9-27] pmol/l) had no significant effect. During gastric lavage at pH 7.0 the median plasma gastrin concentration of the pernicious anaemia patients fell from 320 (63-1760) pmol/l to 125 (46-760) pmol/l (p less than 0.03).