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

Abstract

Abstract. 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.The possibility is discussed that reduced flux of hydrogen‐ions may similarly be responsible for the excretory defect in the duct system of the pancreas.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.