Viscosity and electrolyte concentrations in gastric juice from cystic fibrosis children compared to healthy children.

The viscosity of gastric juice and the concentrations of sodium, potassium, calcium, magnesium and chloride ions were measured before and after stimulation with pentagastrin in 10 children with cystic fibrosis and compared to those in 10 healthy children of corresponding ages. The viscosity values followed the same patterns as those for the sodium and calcium ion concentrations and were higher in the cystic fibrosis group. The electrolyte concentrations in the basal and different post-stimulation fractions of the gastric juice were higher in the cystic fibrosis group. Significant differences between both groups could only be found in the electrolyte concentrations. The total secretion of each of the electrolytes was the same in both groups because along with the increased electrolyte concentration in the cystic fibrosis group there was a reduced volume of gastric juice. The dependence of viscosity on the individual electrolyte concentration is discussed. The differences in the viscosity and the electrolyte concentrations in gastric juice from the cystic fibrosis children seems to be due to changes in the process of gastric secretion and not due to the influence of swallowed saliva.