Talk:Lactic acidosis

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Acidosis is not due to lactic acid[edit]

As I have mentioned on the talk pages of Anaerobic Respiration and Lactic Acid, relatively recent research has clearly established that lactate production in anaerobic respiration does not cause acidosis. The reference I cited there is http://ajpregu.physiology.org/cgi/reprint/287/3/R502.pdf. Lim Wei Quan (talk) 06:44, 30 October 2008 (UTC) Personally until proven otherwise, I think it warrants staying placed on the wiki to keep a 'warning' as the prevailing ideology behind the article vs leaving it otherwise. —Preceding unsigned comment added by 71.61.125.253 (talk) 07:34, 3 January 2009 (UTC)

In humans, perhaps, but lactic acid buildup can cause such extreme acidosis in large reptiles (particularly crocodiles) that it can cause their deaths. See here for a email list posting with direct references to several studies: http://dml.cmnh.org/2001Apr/msg00485.html Since, from this, it's clear that lactic acidosis is real, I'm removing the warning - much of wikipedia is far too human biased anyway. Mokele (talk) 16:00, 31 January 2009 (UTC)
I completely agree with the original comment, acidosis during exercise is not due to lactic acid. This is a widespread misconception, pervasive even in the scientific literature and medicine textbooks. Mokele, you are right that exercise (vigorous muscle contraction) does acidify blood; this is what your text on reptiles show, and this is well known in sports medicine. Concomitantly, exercise also produces large amounts of lactate, but this does not mean that lactate itself is the cause of low pH. The acidification is in fact due to slower removal of protons, which happens in anaerobic conditions because mitochondrial respiration is hampered. I am editing the article to better reflect this fact.Rollowicz (talk) 10:02, 27 December 2009 (UTC)
I reverted, because there's no reference for this. Can you supply a reference to the claim? I'm skeptical it has anything to do with mitochondria, simply because it occurs to the greatest degree (lethal blood acidification) in animals with the greatest prevalence of FG muscle muscles (which contain minimal mitochondria). Mokele (talk) 16:19, 27 December 2009 (UTC)
Mokele, you reverted my edits before I had the time to insert references. The article by Robergs et al. cited above (http://ajpregu.physiology.org/cgi/reprint/287/3/R502.pdf) is a good review of the literature which clearly shows that lactate formation has nothing to do with acidification. Another good (although quite technical) article is that by Hochachka and Mommsen in Science 1984, http://www.sciencemag.org/cgi/content/abstract/219/4591/1391, which also considers variations on this theme across multiple species and pH ranges. Acidification is due to ATP hydrolysis, which produces one proton per molecule ATP hydrolysed to ADP. In response to your comment, the acidification as such certainly does not require the presence of mitochondria; on the contrary, mitochondrial respiration acts as a proton sink, and prevents acidification. In glycolytic muscle fibers, vigorous contraction produces large quantities of protons from ATP hydrolysis, and glycolysis cannot incorporate these protons back into ATP like oxidative phosphorylation does. Thus, heavy use of glycolytic fibers causes acidification. There is no contradiction in this. Again, lactate production cannot possibly lower pH: lactate is a base, not an acid! Lactic acid, the protonated form, is never produced by lactate dehydrogenase. You can find the correct reaction formula at pH 7 in any biochemistry book, e.g. Stryer. Let me know if you have further questions, so we can reach consensus on this issue. This misconception about lactic acidosis is so prevalent in biomedical literature (even in textbooks and a good number of recent papers) that it would be quite valuable to have a wikipedia page that gives an accurate description. —Preceding unsigned comment added by Rollowicz (talkcontribs) 18:43, 27 December 2009 (UTC)
Thanks for the references, they explained things nicely, and I've reverted my revert. (Sorry for my instant skepticism.) However, they do make the entire page name a bit erroneous. Should we move the page to "exercise-induced metabolic acidosis", and leave a redirect here? Or, considering how long and how prevalent the concept is, should we maintain the page as-is and retain a clarifying explanation? Mokele (talk) 04:15, 28 December 2009 (UTC)
Thanks Mokele. I think we should retain the page name. I agree that the term "lactic acidosis" itself is something of a misnomer, but as you say, this concept has been around for so long that I think terminology is stuck, unfortunately. One could re-interpret the name as "acidosis accompanied by lactate buildup" or some such (it's still true that the pH and lactate are strongly correlated). Also, "exercise-induced metabolic acidosis" is a bit too narrow, as lactic acidosis can be caused by other means, as listed in the article. I'll polish the article some more and fix the references.Rollowicz (talk) 10:27, 28 December 2009 (UTC)

There is no definitive proof that metformin causes lactic acidosis.[edit]

There have been no major cases of metformin causing lactic acidosis, and no trials have found metformin to cause lactic acidosis. It is more of a theoretical risk because it is in the biguanide class of drugs, and phenformin notoriously caused lactic acidosis. —Preceding unsigned comment added by 174.0.58.66 (talk) 05:44, 10 February 2009 (UTC)

The statement above is INCORRECT. See http://jmedicalcasereports.com/content/1/1/126 —Preceding unsigned comment added by 174.119.69.25 (talk) 06:51, 6 October 2010 (UTC)

Pathphysiology - muscle types[edit]

"Also, muscle types that have few mitochondria and preferentially use glycolysis for ATP production (so-called type I fibers) are naturally prone to lactic acidosis." I believe this statement is incorrect. Type 1 (aka slow twitch) are rich in mitochondria; it is the fast twitch types 11x and 11b that have comparatively few mitochondria and preferentially use glycolysis. This is referenced on the Wikipedia entry for muscle: http://en.wikipedia.org/wiki/Muscle#Types —Preceding unsigned comment added by 67.176.94.222 (talk) 19:45, 12 May 2011 (UTC)

Definition of lactic acidosis[edit]

Definition stated in this wiki article is: lactate levels >5 mmol/L and serum pH <7.35

Lactic acidosis is in Soyoral at al. 2011 defined as a blood pH less than 7.35 and a serumlactate more than 2mmol/L

I havent checked it up, just wanted to point that out. I wont edit the wiki article since im not an eng. native speaker nor certain.


Soyoral, Y.U., Begenik, H., Emre, H., Aytemiz, E., Ozturk, M., Erkoc, R., 2011. Dialysis therapy for lactic acidosis caused by metformin intoxication: presentation of two cases. Hum Exp Toxicol 30, 1995–1997. — Preceding unsigned comment added by 130.238.244.160 (talk) 13:02, 13 March 2012 (UTC)

Review[edit]

The most recent core review is here (2010) but I can't currently access it. JFW | T@lk 10:32, 11 September 2013 (UTC)

doi:10.1186/s13054-014-0503-3 - some big names in critical care medicine seem to imply that C&W type A lactic acidosis is not the actual mechanism behind hyperlactataemia in severe sepsis. JFW | T@lk 14:09, 17 September 2014 (UTC)

Updating and fixing[edit]

I had a quick look at the article today while I do a bit of reading myself. I am surprised that the intro said (since October 2010) that lactic acidosis is usually due to D-lactate; in humans that is quite wrong (as Luft demonstrates). The long section about lactic acidosis in ruminants doesn't clarify whether this is D-lactic acidosis (as also discussed briefly by Luft) or whether it is something else altogether. This paper (Owens et al 1998, currently cited) suggests that it's both stereoisomers contributing. JFW | T@lk 14:56, 30 December 2013 (UTC)

I also wonder if we need to discuss the fact that in some point-of-care analysers, other substances (such as ethylene glycol) may masquerade as lactate. I will add it if I find a strong source. JFW | T@lk 15:16, 30 December 2013 (UTC)