urine urobilinogen.....??

[goodies]

why do you get high urine bilirubin and normal/low urine urobilinogen with hepatocellular jaundice?

why is there low urine urobilinogen with obstructive jaundice?

i don't get these urine bili tests for jaundice. can someone please explain the difference between urine bilirubin and urine urobilinogen and why/when you would get each of those and not the other?

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[angel5]

This is what I remember from biochem... (I've completed 1 semester of MS1), so I don't know about the path or physio stuff.

With obstructive jaundice, you have a buildup of conjugated bilirubin in the blood. So, there would be low urobilinogen in the urine because the conjugated bilirubin is backing up and not being metabolized in the gut, so it doesn't get to the intestine where it is convereted into urobilinogen, so less urobilinogen is excreted.

In hepatocellular jaundice there is in an increase in urine bilirubin because there is direct damage to liver cells.

 

[UCLAstudent]

angel5 is right. Conjugated bilirubin is converted into urobilinogen by bacteria in the gut. Some of that urobilinogen is absorbed into the blood and filtered by the kidneys. If the conjugated bilirubin isn't making it to the gut in the first place (as with obstructive jaundice), there will be an associated drop in urine urobilinogen.

 

[Buckeye(OH)]

Well done my allopathic colleagues.

 

[beastmaster]

If you really want to scratch your head for a few minutes, ask yourself why bilirubin is normal despite elevated ALP in a case of hepatocellular carcinoma.

 

[Buckeye(OH)]

I dont know, why?