Biochem 88

Question 1

Describe the CFTR channel

Answer 1

ATP-gated Cl channel that secretes Cl into lungs and GI and reabsorbs Cl in sweat glands

Question 2

Where is the mutated Chloride channel retained in CTFR?

Answer 2

RER

Question 3

Where is the most common deletion of the CFTR gene?

Answer 3

Codon deletion of the phenylalanine at position 508 in the CFTR protein. (Phe508)

UW 1412

Question 4

Increased Na channel reabsorption causes what?

Answer 4

more negative transepithelial potential difference

Question 5

Besides increased Cl concentration in sweat, what else can CF patients present with? Why?

Answer 5

Can present with contraction alkalosis and hypokalemia bc of ECF water and Na loss and concomitant renal K/H wasting.

Question 6

What can sometimes be seen in CF patients on CXR?

Answer 6

Chronic bronchitis and bronchiectasis can lead to a reticulonodular pattern on CXR

Question 7

Why do CF males possibly infertile?

Answer 7

Absence of Vas Deferens

Absent sperm

Question 8

What is the action of N-acetylcystine treatment in CF patients

Answer 8

cleaves disulfide bonds within mucus glycoproteins to loosen mucus plug

Question 9

What other treatment can one give CF patients besides N-Acetylcysteine?

Answer 9

Dornase alfa (DNAse) to clear leukocytic debris