The gram-negative bacterium Vibrio cholerae produces a protein, cholera toxin (Mr 90,000), that is responsible for the characteristic symptoms of cholera: extensive loss of body water and Na+ through continuous, debilitating diarrhea. If body fluids and Na+ are not replaced, severedehydration results; untreated, the disease is often fatal. When the cholera toxin gains access to the human intestinal tract, it binds tightly to specific sites in the plasma membrane of the epithelial cells lining the small intestine, causing adenylyl cyclase to undergo prolonged activation (hours or days).(a) What is the effect of cholera toxin on [cAMP] in the intestinal cells?(b) Based on the information above, suggest how cAMP normally functions in intestinal epithelial cells.(c) Suggest a possible treatment for cholera.

The gram-negative bacterium Vibrio cholerae produces a protein, cholera toxin (Mr 90,000), that is responsible for the characteristic symptoms of cholera: extensive loss of body water and Na+ through continuous, debilitating diarrhea. If body fluids and Na+ are not replaced, severedehydration results; untreated, the disease is often fatal. When the cholera toxin gains access to the human intestinal tract, it binds tightly to specific sites in the plasma membrane of the epithelial cells lining the small intestine, causing adenylyl cyclase to undergo prolonged activation (hours or days).(a) What is the effect of cholera toxin on [cAMP] in the intestinal cells?(b) Based on the information above, suggest how cAMP normally functions in intestinal epithelial cells.(c) Suggest a possible treatment for cholera.

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter3: The Plasma Membrane And Membrane Potential

Section: Chapter Questions

Problem 1ACR: When William H. was helping victims after a devastating earthquake in a region not prepared to...

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When William H. was helping victims after a devastating earthquake in a region not prepared to swiftly set up adequate temporary shelter, he developed severe diarrhea. He was diagnosed as having cholera, a disease transmitted through unsanitary water supplies contaminated by fecal material from infected indiv iduals. The toxin produced by cholera bacteria causes Cl- channels in the lurninal membranes of the intestinal cells to stay open, thereby increasing the secretion of Cl- from the cells into the intestinal tract lumen. By what mechanisms would Na+ and water be secreted into the lumen in conjunction with Cl- secretion? How does this secretory response account for the severe diarrhea that is characteristic of cholera?
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