cftr - doc_mrv

[ArchivalUser]

iam confused with CFTR function.how does it differs in sweet glands when compared to other ducts in CF ? ANYONE HELP ME PLZ

[ArchivalUser]

cftr gene mutation causes misfolding of the cl- channel protein. so this protein will be degraded, you know where, right? so it causes more cl- in sweat. I don't think there is any difference in the function of the same channel in different places as you see CF has different manifestions. cl- channels are more in sweat glands so it's more obvious there. i'm not sure if I'm getting your question though.

[ArchivalUser]

ok, i will try to explain.

CF si an autosomal recessive dz.
primarily affects whites
3 nucleotide deletine on chromosome 7.(normallly code for phenylalanine)

IMPORTANT MECHANISM IN CF is defective CF transmembrane conductance regulator for chloride ions.

In sweat glands: there is loss of CFTR Cl- , which causes----->decreased Na and Cl- reabsorption in sweat glands-----so there wud be increase in Cl- in the sweat (which forms the basis of SWEAT TEST IN CF)

In exocrine glands: the effect of loss of CFTR Cl- causes an increased Na and water reabsorption and also DECREASED Cl- SECRETION. so the net effect is dehydration of body secretions in d/t lack of NaCl-------secretions are dehydrated in bronchioles, pancreatic ducts (type 1 DM), bile ducts (assoc. with secondary biliary cirrhosis) meconium ileus (small bowel obstruction in newborns).


hope it helps, doc_mrv.

[ArchivalUser]

due to mutation of CFTR ,results in isotonic luminal content in exocrine glands and results in thick mucus ,but in sweatglands it is hypertonic luminal fluid.
can u plz explain which directn chloride,sodium and water move across luminal membranes in exocrine and sweat glands before and after mutation.

[ArchivalUser]

CFTR (cystic fibrosis transmembrane conductance regulator, ATP-binding cassette (sub-family C, member 7)) is a human gene that provides instructions for making a protein called the cystic fibrosis transmembrane conductance regulator. This protein functions as an ion channel across the cell membrane. Such channels are found in tissues that produce mucus, sweat, saliva, tears and digestive enzymes. Chloride, a component of salt, is transported through the channels in response to cellular signals. The transport of chloride helps control the movement of water (osmosis) in tissues and maintain the fluidity of mucus and other secretions. The CFTR protein also regulates the function of other channels, such as a type of channel that transports sodium across cell membranes. Normal functioning of these channels ensures that organs such as the lungs and pancreas function properly.