SALIVA, TEARS AND DUODENAL CONTENTS IN CYSTIC FIBROSIS OF THE PANCREAS

Abstract

Analyses of the concentrations of chloride and sodium in mixed saliva support the conclusion that patients with cystic fibrosis of the pancreas show higher mean values than do control subjects. Salivary potassium does not vary significantly in the two groups. Concentrations of chloride and sodium in tears were also found to be significantly increased as compared with controls. Potassium concentrations in tears are similar in the two groups. The overlap in concentrations of chloride and sodium in both saliva and tears is considerable in the two groups of subjects, thus detracting seriously from the value of these determinations in differentiation of cystic fibrosis from other diseases. This is in contrast to the consistent difference, with virtually no overlap, found in the concentration of chloride and sodium in the sweat of patients with cystic fibrosis as compared with other conditions, and the consequent use which is made of the "sweat test" as a reliable diagnostic procedure. Parotid secretory rates have been found to be significantly increased in patients with cystic fibrosis over those of controls. Amylase and lysozyme activity in parotid and mixed saliva were no different in patients with cystic fibrosis and controls. Concentrations of chloride, sodium and potassium in duodenal fluid were found to be essentially the same in patients with cystic fibrosis as in controls, differing only mildly from concentrations of these ions in plasma. Among patients with cystic fibrosis, wide variations in the proteolytic activity of the duodenal fluid were not accompanied by corresponding variations in the concentration of chloride, sodium and potassium. In the generalized disease termed cystic fibrosis of the pancreas there are thus three defects in secretion of exocrine glands which require explanation: an abnormality in mucus secretion; abnormally high electrolyte concentrations in sweat, saliva and tears; and an increased rate of secretion of the parotid glands.