Monday, April 16, 2012

Glucose question

Glucose question?
If the kidneys normally reabsorb all the glucose present in the filtrate, explain why patients with diabetes mellitus exhibit high glucose levels in their urine, despite having normal kidney function. Why does this happen? Help plz.
Biology - 3 Answers
Random Answers, Critics, Comments, Opinions :
1 :
Because kidney tubules do not able to absorb glucose in Diabetes Mellitus.
2 :
Hmmm...I am a nurse...I don't know the exact answer, but it seems to me that in people with DM, their blood glucose levels are so high, the increased sugar flowing through the kidneys causes an increase in urine production through osmosis. The sugar draws in a lot of extra water, so that is why there is an increase in urine output. Yes normally the urine does not contain glucose but in diabetes, the sugar concentration in the blood is so high that it has to spill out some how.
3 :
The amount of glucose that can be absorbed back into the bloodstream is related to the amount of glucose already in the blood. The activities of the kidney rely mostly on concentration gradients for the absorption of various nutrients and minerals back into the blood. (There is some active transport, but even that can be affected by concentrations in the blood.) Insulin is the hormone that sends signals to cells to pull glucose out of the blood. So when glucose levels are low, or the body cannot respond to glucose (both of which are causes of diabetes), blood glucose levels remain high. This elevated concentrations of glucose make it much more difficult for the kidneys to remove glucose from urine (because it cannot go against the concentration gradient), and thus, even though the kidney's are acting normally, they simply cannot over come the concentration gradient of glucose between the blood and the urine.

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