madonna che ignurant... :-(

[mike2000]

ehm....scusate ma cosa sono i chetoni? come e quando intervengono? perchè? come si fanno "uscire"? sono fondamentali? ditemi tutto e di più (se ne avete voglia ovviamente ). Thanks!!

[Gawain]

"Ketone bodies are produced in the liver, mainly from the oxidation of fatty acids, and are exported to peripheral tissues for use as an energy source.
They are particularly important for the brain, which has no other
substantial non-glucose-derived energy source."

Una spiegazione piuttosto stringata, ma efficace, del metabolismo chetonico è in un articolo che ho scaricato qualche anno fa e che incollo qui di seguito. Viene anche spiegato perchè la chetoacidosi è impossibile in soggetti non diabetici del tipo I.



Ketones
Arturo R. Rolla, MD

Ketones, ketones! So much interest for these little buggers! I hate them
because for me they always mean trouble. Nevertheless, since so many of you
are so interested, let's talk some more about them.

What we call ketones are really two acids and a ketone. The acids are called
hydroxybutyric and acetoacetic. Butyric is related to butter because it's
formed in rancid butter from the milk fat. Acetoacetic is related to the
acid in vinegar. The ketone is acetone, the same that is use to clean up
nail polish.

The ketoacids are short - they are four carbons long. This is important
because in that way they are able to penetrate cells to feed them when there
is no sugar. The fat stores accumulate fat as very long fatty acids. They
are hard to digest - if you know what I mean - because they are so long. So,
in situations of energy crisis (not enough food, not enough sugar), the fat
cells start releasing these long fatty acids into the blood.

To be used, particularly by the brain, the fatty acids go to the liver where
they are literally cut into two carbon fragments (ketoacids). They are then
utilized (burned) by many tissues, including the brain. The brain can do its
computer work equally as good being fed sugar or ketones! Isn't that
remarkable? You can be a mathematics genious while starving and your brain
is consuming short fats.

If the production of ketoacids equals the utilization of ketones by the
tissue, there is no problem. They don't accumulate in the blood, and some of
the ketoacids are excreted in the urine. (You test positive with Acetest or
Ketodiastix). This is exactly what happens during starvation in a
non-diabetic person.

In IDDM without insulin, the levels of insulin in the blood are so low that
the release of fatty acids from the fat stores is massive. The liver can
then only produce tremendous amounts of ketoacids because it has to get rid
of all this extra fat. The production of ketoacids is therefore exaggerated.

At the same time, the tissues decrease their utilization of ketoacids, and
they start accumulating in the blood. This constitutes an "acid pollution"
as a result of the burning of fat. As long as you can excrete them in the
urine, you are OK. But because of all the sugar in the urine, you start
getting dehydrated and the kidneys run out of water to make more urine.

At that point, the kidneys cannot excrete ketoacids as well. They pile up in
the blood and start making it acid ---> Ketoacidosis is the name! Voila!

Ciao!!!

[mike2000]

thanks