Biomedical Engineering: Bridging Medicine and Technology 1st Edition by Veronique Tran,Mark Saltzman

Exercise 21

Cholera is a pathogen that infects the intestine, producing a toxin that blocks one of the G proteins (preventing normal cycling), and locks a Cl channel open (the same channel that is involved in cystic fibrosis: CFTR channel). Water reabsorption is severely impaired. Patients die of dehydration, some- times losing liters of fluid within a few hours. Why would blockage of an ion channel effect water reabsorption?