Re: Research regarding kidney failure: I´m perplexed

"Liz" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Last night I was watching Animal Planet when I learned that reseachers
> are studying the biochemistry of polar bears because they may find
> something that may be beneficial for kidney failure patients.
>
> This is what got their interest: polar bear will hybernate during the
> winter without defecating or urinating.
>
> What I know regarding polar bears is that they will gain a lot of fat
> during the warmer months to be able to withstand hybernation. When
> food is abundant, he will eat mostly the fat and leave the meat and
> bones behind.
>
> Now here are my questions:
>
> If one does not eat, one does not defecate. If the polar bear is not
> eating during his hybernation, why should he defecate?
>
> Burning fat will result in carbon dioxide and water. Carbon dioxide is
> eliminated by lungs and water is also partly eliminated by lungs. The
> bear is not drinking water during his hybernation so there is no real
> need to urinate. Fat, unlike protein, will not generate urea.
>
> Did I miss something or are they waisting time and money with
> something stupid?
The urea level or BUN is used as a measure of glomerular filtration under
normal circumstances.  Renal failure is not caused by elevated urea but the
other way around. There are other waste products produced by daily
metabolism that are toxic to the body and need to be excreted by the body
and BUN is an easy marker for this.
The cholesterol system in these bears is also interesting so in short they
are two different species but the study of one might lead to a temporary
relief in the other.