"Sucrose gap" technique for measurement of focal gastric mucosal potential differences in the rat.

Bile salts, mechanical trauma, and ischemia were used to produce focal alterations in rat gastric mucosa in a chamber preparation. Gastric mucosal to serosal potential difference (PD) was measured from both treated and untreated areas using electrodes in contact with the mucosal surface. The sensitivity of the measurements was increased if a nonconducting solution (isotonic sucrose) was used to isolate electrically the control from the experimental sites. This "sucrose gap" technique thus allows the identification of focal areas of gastric mucosa with an altered PD. In addition, this technique was used to measure the PD of the forestomach, fundus, and antrum of the rat, and to demonstrate that atropine and pentagastrin influence the PD only in the fundus.