Acid secretion, potential difference, and resistance of elasmobranch stomach.

REHM, WARREN S. Acid secretion, potential dzyerence, and resistance of elasmobranch stomach. Am. J. Physiol. 203(6) : I ogr 1°931962. -The present report is concerned with in vitro studies on gastric mucosa of the skate, Raja eglentaria, the electric ray, Narcine bra,&hsis, and the shark, Negaprion breuirosfris, Maximum secretory rates of from 0.65 to 2.7 PEq hr-l cmm2 were found. An increase in the secretory rate from an initial low level was associated with an increase in potential difference (PD), a decrease in resistance, and an increase in the calculated short-circuit current. The average PD and resistance before the increase in the secretory rate was 2.2 mv (nutrient positive) and 268 ohms cm 2. After the increase they were 6.4 mv and I gg ohms cm2. Thiocyanate (IO-~ M) to nutrient resulted in a decrease of secretory rate to zero and an increase in PD and resistance. The results can be explained on the basis of the separate mechanisms theory of Hf and Clion secretion on the assumption that the resistance in the Clion limb of the circuit is considerably lower than that in the H+ ion limb of the circuit.