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Mmm ... lactic acid.
May 17, 2006 10:40 AM   Subscribe

Researchers discover that lactic acid is more than just a byproduct. According to George A. Brooks, "lactate is the link between oxidative and glycolytic, or anaerobic, metabolism." You can read the abstract of the paper at the American Journal of Physiology - Endocrinology and Metabolism.
posted by monju_bosatsu (19 comments total) 1 user marked this as a favorite

 
Wasn't this already known?
posted by 517 at 11:00 AM on May 17, 2006


Cool - I found the second link informative, especially after being un-impressed by the NYT article yesterday. I'm not sure if this will have any real-world ramifications for training athletes, but it's still interesting.

The title of the post reminded me that lactic acid is also a tasty component of Berliner Weisse... mmm beer.
posted by exogenous at 11:00 AM on May 17, 2006


I think it's been known for at least the last couple of years, 517, as I was taught in my Exercise Physiology class that lactic acid provides carbon skeletons for gluconeogenesis as part of the "intracellular lactate shuttle" mentioned in the abstract. This more recent research appears to reveal the mechanism behind the shuttle. So it looks like they've figured out the how of it, though it's function is already known. Not suprised if the athletic world isn't quite aware of it right now, my professor said it was a fairly recent discovery.
posted by Mister Cheese at 11:12 AM on May 17, 2006


517- it was only just recently discovered that there is a mitochondrial machinery for using lactate as an energy source, in a way that is coupled to lactate production.
posted by rxrfrx at 11:12 AM on May 17, 2006


It does illuminate there is a flaw in the way current science is administrated. "I had huge fights, I had terrible trouble getting my grants funded, I had my papers rejected". The unlikeliness of the hypothesis within the dominant theoretical model made funding research more difficult, and ultimately delayed the discovery of a physical process.

However, the jocks got it right anyway.

Hmm.
posted by dash_slot- at 11:17 AM on May 17, 2006


How will this information be used to opimize training?
posted by caddis at 11:22 AM on May 17, 2006


"intracellular lactate shuttle"

That's what I am remebering.
posted by 517 at 11:23 AM on May 17, 2006


Woo, spell check.
posted by 517 at 11:24 AM on May 17, 2006


Caddis, it looks from the full text of the paper that the denser your mitochondrial matrix, the more you have of mitochondrial lactate complex that. Since the intracellular lactate shuttle appears to transfer the necessary products for gluconeogenesis, the denser the mitochondrial matrix, the more mitochondrial lactate complex you have, leading to a more efficient shuttle. This is probably most useful during endurance exercise, where the body needs to scrounge about for fuel for the muscles. I don't know if this knowledge could be used to optimize training in a big, revolutionary way, because endurance training is known to incite the body to create a denser mitochondrial matrix anyway.

Oh, wait, the second link basically says this already. Well, at least I can still understand research papers.

Pretty cool stuff.
posted by Mister Cheese at 11:50 AM on May 17, 2006


This might be well-known in the exercise field, but the intro biology text I used to teach last semester didn't have anything in it except the old "Lactate is bad" thing. This is news to me - always interesting to see a theory we "know" to be true overturned by new evidence. Guess I have to update my lecture notes for the next time through - as if cellular respiration didn't give my students enough trouble to begin with!
posted by caution live frogs at 1:28 PM on May 17, 2006


Holy cow! That's amazing! I can't believe it!



...Now will someone explain what the hell that means?
posted by lumpenprole at 2:24 PM on May 17, 2006


The "wall" between aerobic squishies (air-breathers like us) and anaerobic squishies (many microorganisms, including yeast) isn't thought to be as impervious as it used to be. It actually is pretty interesting, and I can't help but wonder what this will do for advances in brewing and/or distilling practices, potentially. And the exercise thing of course.
posted by bardic at 2:28 PM on May 17, 2006


What's new here is only the discovery of the mechanism. That lactic acid is used by the body for another go-around at the energy cycle has been known for at least a decade. It was one of the topics of a detailed Bicycling magazine article waaaaay back when.
posted by five fresh fish at 4:35 PM on May 17, 2006


Hmmm... been known for the last decade or so, eh? What's interesting to me is the sort of lag between these sorts of publications and their appearance in textbooks. I know back in High School (five years ago) that our biology texts still said "lactic acid is a bad thing."
posted by Mister Cheese at 5:04 PM on May 17, 2006


Yes, I got that from the article. My question is given that we already know how to make them more dense through interval training (perhaps we didn't know what it was doing but knew it worked) how will this new knowledge translate into improved training. Perhaps it can help through testing for levels of mitochondria and correlation of training regimens with those levels, but is there more?
posted by caddis at 6:38 PM on May 17, 2006


It does illuminate there is a flaw in the way current science is administrated. "I had huge fights, I had terrible trouble getting my grants funded, I had my papers rejected". The unlikeliness of the hypothesis within the dominant theoretical model made funding research more difficult, and ultimately delayed the discovery of a physical process.

This kind of thing always reminds me of H. Pylori and the struggle to get it recognized by the medical community as a primary cause of ulcers (90% for duodenal and 80% for gastric). But this usually gets passed off as the system "working" in that new claims have to be proven. And reproven. And then petri dishes swallowed, apparently.
posted by dreamsign at 8:57 AM on May 18, 2006


You know what this means right?!
Finding a non-aerobic way to get energy to mitachondria means science is one step closer to being able to animate corpses and create real zombies!
posted by -harlequin- at 6:30 PM on May 18, 2006


Now all we need is a bacterial infection that produces lactic acid as a byproduct of breaking down fats... and a few gazillion other technologies, and teh Zombie Plague will be upon us.

Better start preparing for the apocalyse now...

:)
posted by -harlequin- at 6:32 PM on May 18, 2006


This is very old news.

I've been teaching thisd version of oxygen debt for literally decades, and I'm pretty sure that I learned it way back as a college freshman. Lactic acid was known as a stalled intermediate (slightly processed, at a point that would ordinarily be pyruvic acid) of the muscles when performance exceeded oxygen supply, and the "debt" was paid off by feeding it back (as an aerobic fuel) into the Krebs cycle - that's where the whole concept of oxygen debt originates!

I'd think that any problem this guy had getting funding was from people who knew that he was reinventing the wheel. It demonstrates that human cluelessness is not confined to early American Idol rejects.
posted by DarbyMac at 6:26 AM on May 20, 2006


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