Physiologic process similar to Lactulose effect on Hepatic Encephalopathy! - USMLE Forums
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Old 07-04-2011
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Liver Physiologic process similar to Lactulose effect on Hepatic Encephalopathy!

Which of the following normal physiologic processes most closely parallels the mechanism by which lactulose exerts its effects in hepatic encephalopathy?

A) CNS regulation of carbon dioxide levels.
B) Duodenal metabolism of sucrose.
C) Gastrocolic reflex.
D) Renal buffering of increased acid load.
E) water resorption by the colon.
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Old 07-04-2011
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D...............
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Old 07-04-2011
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I think its E..
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Old 07-04-2011
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Quote:
Originally Posted by mayursn39 View Post
Which of the following normal physiologic processes most closely parallels the mechanism by which lactulose exerts its effects in hepatic encephalopathy?

A) CNS regulation of carbon dioxide levels.
B) Duodenal metabolism of sucrose.
C) Gastrocolic reflex.
D) Renal buffering of increased acid load.
E) water resorption by the colon.
the ans is D the lactulose is converted by gut bacteria into latic acid which generates acidic ph n NH3 is converted into NH4+ ion which is water soluble n xcreted by kidney n same happens in renal buffer of NH3/NH4Cl
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Old 07-04-2011
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i completely agree with qurat21 it is d
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Old 07-04-2011
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i think its D
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Old 07-04-2011
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I also think is D)
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Old 07-05-2011
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my answer is D) Renal buffering of increased acid load.
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Yes D is the answer and qurat21 explains it to some extent..
In intestine lactulose is converted to lactic acid which generates H+.
NH3 + H+ = NH4+ which cannot be absorbed back into the circulation as it is in cation form..

In kidneys. NH3 is formed from glutathione at the DCT / collecting Duct. and excreated in the tubule.
this then reacts with H+ ions in the tubule to form the NH4+ ion buffering the acid in the tubule..
(THIS IS CALLED AMMONIA TRAP)
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