Effects of NaSCN and omeprazole on resistance and potential of fundus of Rana pipiens.

Thiocyanate (SCN) produced a rapid inhibition of acid secretion and a concurrent rapid increase in the transmucosal potential difference (PD) and resistance. After inhibition, resistance rapidly peaked and then decreased. In contrast, omeprazole produced a slow inhibition of secretion and a slow increase in PD and resistance. The peak increase in resistance with SCN was significantly greater than the steady-state increases for both SCN and omeprazole. All increases were significant. The increases in PD and resistance are greater at high H+ rates than at low H+ rates. We postulate that the peak SCN increase in resistance is due to the increase in resistance of the secretory membrane, which is followed by a decrease in resistance of the nutrient membrane. On this basis the omeprazole increase in resistance that occurs concurrently with the slow decrease in the H+ rate is a result of a concurrent change of the resistances of the two opposing membranes.