lactic acidosis from lactate buildup

[Interprete]

Hello,

There is much talk in various medical sources about so-called lactic acidosis being caused by lactic acid buildup following anaerobic glycolysis (see for example here or here).

Then you have other, more biochemistry-focused sources explaining that what comes out of glycolysis is pyruvate (i.e. COO-), NOT pyruvic acid (COOH), and it is reduced into lactate (COO-), not lactic acid, which means that the molecule is already inonized and cannot further release any additional proton that would acidify the medium.

What do you make of all this? There seems to be a major contradiction here and it’s strange that I can’t find anything on this issue anywhere online.

Thanks!