In vitro effects of gastrin on the movement of electrolytes across the human colon.

Using an in vitro system, the effect of gastrin on the colonic handling of water and electrolytes has been investigated. Gastrin converted the normal mucosal absorption of water and sodium into a net secretion. The colonic response to gastrin was done-related with respect to sodium, and the effects were greater when it was added to the serosal side. The potassium handling of the isolated colonic mucosa was not altered by gastrin. At a concentration of 800pg/ml, gastrin signficantly reduced the normal movement of sodium from mucosa to serosa (absorption) but significantly increased serosal to mucosal movement (secretion). This alteration in the bidirectional flux of ions under the influence of gastrin may be clinically important and could account in partt for the diarrhoea associated with the Zollinger-Ellison syndrome.