Effect of 16,16-dimethyl prostaglandin E2 on gastric epithelial cell membrane potentials and resistances.

Intracellular microelectrode techniques were employed to examine the effects of 16,16-dimethyl prostaglandin E2 (dmPGE2) on Necturus antral mucosa epithelial cell membrane potentials and resistances. Necturus antral mucosa was mounted in a modified Ussing chamber and stable intracellular impalements were obtained. Addition of 0.01 microgram/ml dmPGE2 to the mucosal solution produced an increase of the apical cell membrane potential (Vmc) from -44.3 +/- 3.1 to -53.5 +/- 3.8 mV (p less than 0.001) and of the basolateral cell membrane potential (Vcs) from -48.8 +/- 2.8 to -57.7 +/- 3.2 mV (p less than 0.001). This reversible, dose-dependent hyperpolarization of both cell membranes was accompanied by a decrease in the electrical resistance of the apical membranes (Ra) from 2550 +/- 250 omega/cm2 to 1870 +/- 210 omega/cm2 (p less than 0.05) and a decrease in the resistance of the basolateral membrane (Rb) from 1020 +/- 250 omega/cm2 to 630 +/- 80 omega/cm2 (p less than 0.05). In addition, there was an increase in the resistance of the shunt (intercellular junction, Rs), the major route of transepithelial ion flow, from 710 +/- 60 omega/cm2 to 750 +/- 80 omega/cm2 (p less than 0.05). Thus dmPGE2 increased the cell membrane potentials and reduced the ionic permeability of the intercellular junction.