Micropuncture study of excretion of water and electrolytes by the pancreas.

p‘ MANGOS, JOHN A., AND NONA K. MCSHERRY. Micropuncture study of excretion of water and electrolytes by the pancreas. Am. J. Physiol. 22 l(2) : 496-503. 197 l.‘I’he monovalent ionic composition of the primary secretory (acinar) fluid and the transductal fluxes of monovalent ions and water in the duct system of the rat and rabbit pancreas were investigated by using micropuncture and microanalytical techniques. The concentrations in the acinar fluid were: Rat: [Na] 149.0 rfr 3.8, [K] 6.7 ZfI: 1.1, [Cl] 113.6 & 3.9, and [HCOS] 37.8 sfi 2.1 mEq/liter. Rabbit: [Na] 157.4 rt 3.2, [K] 3. I =t 0.56, [Cl] 42.9 + 2.8, and [HCOS] 111.4 =t 6.2 mEq/liter. The simultaneous measurements of the concentrations of the above ions in the acinar fluid and in the final pancreatic juice showed that a) there were no net transductal fluxes of the cations Na and K in the pancreas of both species, and b) the transductal fluxes of anions were different: in the rat pancreas influx of HC03 and efflux of Cl occurred; in the rabbit pancreas, influx of Cl and efflux of HCO; were observed. These opposing anionic transductal fluxes in the pancreas of two species of rodents are similar to those observed between the human pancreas and the pancreas of dog and cat.