Suggestion of an abnormal anion exchange mechanism in sweat glands of cystic fibrosis patients.

Abstract

Summary: The physiological basis for the defect in NaCl reabsorption in cystic fibrosis (CF) sweat glands is not known. We have systematically followed the concentrations of the three major inorganic electrolytes in sweat as a function of single gland sweat rate in patients with CF and normal individuals. The result demonstrates that (1) at low sweat rates, sweat glands of CF individuals can reduce NaCl concentrations to normal levels and (2) that the concentration of organic anions and/or HCO3 in CF sweat is substantially less than in normal sweat. Speculation: Present data and other findings suggest that Na/K transport and a postulated Na/H exchange are normal, but that a postulated anion exchange may be defective in cystic fibrosis sweat glands. These observations suggest an underlying transport genetic abnormality, which might explain observed abnormalities in cystic fibrosis exocrine gland secretions in general.