Question

messenger\ cyclic adenosine monophosphate (camp) that activates an intestinal crypt cell chloride ion channel, thereby resulting in massive fluid and electrolyte secretion into the lumen of the gut.

raufman, j. p. (1998). cholera. am. j. med. 104, 386–394.

based on the information above, which of the following is most likely to be observed in the intestinal environment of a person infected with cholera?

choose 1 answer:
a elevated levels of intracellular atp
b elevated levels of extracellular chloride ions
c reduced levels of intracellular camp
d reduced levels of extracellular chloride ions

Explanation:

1. Analyze Option A: The passage talks about cAMP activating a chloride ion channel, not about intracellular ATP levels. So elevated intracellular ATP is not supported, eliminate A.
2. Analyze Option B: The passage states that cAMP activates an intestinal crypt cell chloride ion channel, leading to massive fluid and electrolyte (including chloride ions) secretion into the gut lumen (extracellular environment for the gut). So extracellular chloride ion levels should be elevated, B is a strong candidate.
3. Analyze Option C: The passage says cAMP is the "messenger" that activates the channel, so during cholera infection, cAMP should be active (not reduced) to cause the secretion. So reduced intracellular cAMP is incorrect, eliminate C.
4. Analyze Option D: Since chloride ions are secreted into the gut lumen (extracellular), their levels should increase, not decrease. So reduced extracellular chloride ions is incorrect, eliminate D.

Answer:

B. Elevated levels of extracellular chloride ions