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Normal Physiology: Effects of normal total CFTR activity

The CFTR gene is expressed in epithelial tissue of multiple organs throughout the body. The cystic fibrosis transmembrane conductance regulator, or CFTR, channel plays an important role in maintaining electrolytes and fluid balance in many organ systems. The regulated transport of electrolytes and fluid is necessary for the proper function of the airway, pancreas, gastrointestinal tract, and sweat glands, among others. In individuals without CF, normal expression of CFTR protein and normal CFTR activity contribute to the proper function of these organs.1-5

Normal Physiology2-4

How does normal total CFTR activity contribute to proper organ function?

Click the circles on the body to review.
CFTR proteins help regulate salt and water balance, which contributes to normal mucus hydration and clearance from the sinonasal passages
CF Physiology
CFTR proteins regulate transport of chloride and bicarbonate to maintain a normal volume and pH of pancreatic secretions necessary for digestion of nutrients
CF Physiology
Gastrointestinal Tract
CFTR-regulated balance of electrolytes and fluid allows for normal hydration and appropriate intestinal pH, as well as normal composition of intestinal secretions
CF Physiology
Sweat Glands
In the sweat duct, chloride passes through the CFTR channels following sodium absorption, to maintain normal sweat chloride levels
CF Physiology
CFTR proteins help regulate salt and water balance, which contributes to normal hydration of airways and normal mucociliary clearance
CF Physiology
Reproductive System
CFTR regulation of chloride and bicarbonate transport helps foster normal development of vas deferens in males; CFTR-regulated salt and water balance helps to hydrate cervical mucus in females
CF Physiology

Learn more about CFTR mutations.

  1. Zielenski J. Genotype and phenotype in cystic fibrosis. Respiration. 2000;67(2):117‐133.
  2. Ramsey B, Richardson MA. Impact of sinusitis in cystic fibrosis. J Allergy Clin Immunol. 1992;90(3 Pt 2):547-552.
  3. Moskowitz SM, Chmiel JF, Sternen DL, et al. Clinical practice and genetic counseling for cystic fibrosis and CFTR-related disorders. Genet Med. 2008;10(12):851-868.
  4. Welsh MJ, Ramsey BW, Accurso F, Cutting GR. Cystic fibrosis: membrane transport disorders. In: Valle D, Beaudet A, Vogelstein B, et al, eds. The Online Metabolic & Molecular Bases of Inherited Disease. The McGraw‐Hill Companies Inc; 2004:part 21, chap 201.
  5. Quinton PM. Cystic fibrosis: a disease in electrolyte transport. FASEB J. 1990;4(10):2709-2717.