Diminished excretion of bicarbonate from the single sweat gland of patients with cystic fibrosis of the pancreas.

Using pH-microelectrodes the excretion of hydrogen-ions and bicarbonate in relation to flow 
rate was investigated in a single sweat gland of cystic fibrosis 
children. The results show decreased excretion of hydrogen-ions and an increased 
excretion of bicarbonate. Evidence is presented that due to reduced secretion 
of hydrogen-ions in the duct both the reabsorption of sodium and 
the secretion of potassium may be impaired. Reduced flux of protons 
across the luminal membrane of epithelial cells is proposed as a 
general feature of exocrine gland defects. It is then possible to 
describe both the cationic transport defect of the sweat gland duct 
and the anionic bicarbonate-secretory defect in one term. 