tasneembanu
Forum Guru
Topics: 96
Posts: 545
|
what is teh channel affected in Cystic fibrosis
1.Ca2+ activated Cl secretion
2.Ca2+ activated Cl uptake
3.cAMP stimulated Cl secretion
|
| dariush
Forum Elite
Topics: 20
Posts: 356
|
3. aka CFTR
___________________
Allah (God) is watching over us...
|
| bm
Forum Elite
Topics: 37
Posts: 421
|
cAMP stimulated Cl secretion
|
| BumbleB
Forum Junior
Topics: 2
Posts: 83
|
Bcos most common mutation is in the nucleotide binding domain (cAMP-nucleotide)
|
| Malaysian
Forum Guru
Topics: 28
Posts: 778
|
So when the mutation occurs does this mean the Cl- channels stop secretions???In that case why in the sweat test is there increased Cl- and Na+ in the sweat and its mentioned in BRS its because of lack of uptake in sweat of cloride and sodium?????
What really happens in CFTR gene mutation to the receptor??????
|
| BumbleB
Forum Junior
Topics: 2
Posts: 83
|
The Cl- channel is "backwards" in sweat glands, that is it actually REABSORBS Cl- from sweat, but in other tissues it excretes Cl-.
What happens to the receptors is this: the cell somehow recognizes that the channel is mutated and it never (90%) leaves the ER where it is made.
So basically people with CF just lack this channel in their cell surface and can't get the "right" Cl- concetration in their secretions.
Remember they have too much Cl- in sweat (salty sweat), and not enough of it in mucus, so low Cl- in mucus leads to low water in the mucus because Na and Cl- are the ions that drive water into the mucus. So the thick mucus prevents the CF pts from 1. Breathing well, 2. secreting digestive enzymes from the pancrease, 2. reproducing (in males the vas deferens are "clogged"
check out this page for a more "formal" explanation: http://www.merck.com/mrkshared/mmanual/section19/...
|
| Malaysian
Forum Guru
Topics: 28
Posts: 778
|
Wow..thanks bumblebee you explained it so well I don't think I'll need to read your link!
Then since the cAMP chloride channels are affected in these patients(which are also the channels activated during diarrhoea)can it be hypothetically be said that these patients don't develop diarrhoea and so immune to cholera??
|
| BumbleB
Forum Junior
Topics: 2
Posts: 83
|
Perhaps cf heterozygotes have some kind of advantage?
check this out: http://wsrv.clas.virginia.edu/~rjh9u/cysfib.html
http://serendip.brynmawr.edu/biology/b103/f02/web...
|
| Malaysian
Forum Guru
Topics: 28
Posts: 778
|
Very interesting...thanks once again
|
|
| |
| | | | | | | | | |
