[Methylglyoxal--a test for impaired biological functions of exotrophy and endoecology, low glucose level in the cytosol and gluconeogenesis from fatty acids (a lecture)].

In philogenesis, due to the failure to store a great deal of carbohydrates in vivo as glycogen, all animal species began synthesizing from glucose palminitic fatty acid and depositing it as triglycerides. During biological dysfunction of exotrophy (long starvation, early postnatality, hibernation), cells also accomplish a reverse synthesis of glucose from fatty acids under aerobic conditions. Under physiological conditions, acetyl-CoA that is converted to malate and pyruvate in the glyoxalate cycle is a substrate of glyconeogenesis. Under pathological conditions of hypoxia and deficiency of macroerges, gluconeogenesis occurs without ATP consumption through the methylglyoxal pathway when used as a substrate of ketone bodies via the pathway: butyric acid (butyrate) --> beta-hydroxybutyrate --> acetoacetate --> acetone --> acetol --> methylglyoxal --> S-D-lactol-glutathione --> D-lactate --> pyruvate --> D-lactate. Under physiological conditions, this gluconeogenesis pathway does not function. We believe that with low glucose levels in the cell cytosole (glycopenia), under pathological conditions of hypoxia and due to failure to mitochondria to oxidize fatty acids, gene expression and gluconeogenesis occur through the methylglyoxal pathway. At the same time, the cytosol, intercellular environment, and plasma shows the elevated levels of methylglyoxal and D-lactate that it is converted to by the action of glyoxalases I and II. Under pathological conditions, glycopenia develops in starvation, diabetes, and metabolic acidosis, neoplasms, renal failure, and possibly, metabolic syndrome. The chemical interaction of methylglyoxal with the amino acid residues of lysine and arginine results in the denaturation of circulating and structurized proteins via carbonylation--glycosylation.

[Methylglyoxal--test for biological dysfunctions of homeostasis and endoecology, low cytosolic glucose level, and gluconeogenesis from fatty acids].

If a lot of carbohydrates cannot be in vivo stored as glycogen, the synthesis of palmitic fatty acid (FA) from glucose and its adipocyte deposition as triglycerides are under way in phylogenesis. With impaired biological function of exotrophy (fasting, early postnatality, hibernation), the cells perform a reverse process--the synthesis of glucose from FA. Physiologically, the substrate of gluconeogenesis is acetyl-CoA that is converted by the malate --> 9 piruvate --> glucose pathway in the glyoxalate cycle. Under the pathological conditions of hypoxia and energy deficiency, gluconeogenesis occurs without ATP consumption via the methylglyoxalate pathway (MGP) while using as a substrate of ketone bodies: butyric acid (butyrate) --> beta-hydroxybutyrate --> acetoacetate --> acetone --> acetol --> methylglyoxal (MG) --> S-D-lactolglutathione --> D-lactate --> piruvate --> D-lactate. Under physiological conditions, this pathway of gluconeogenesis does not work. The authors hold that gene expression and gluconeogenesis occur via the MGP when glucose levels are low in the cell cytosol (glycopenia) and FA cannot be oxidized in the mitochondria. Cytosol, intercellular medium, plasma show elevated levels of MG and D-lactate, to which it converts under the action of glyoxalases I and II. Glycopenia develops in fasting, diabetes mellitus, metabolic syndrome, renal failure, phenofibrate therapy, impaired function of exotrophy--excessive dietary intake of saturated and trans fatty acids. The chemical interaction of MG with amino acid residues of lysine and arginine leads to protein denaturation during carbonylation--glycosylation and impaired biological function of endoecology. The determination of plasma MG and D-lactate may be a test for glycopenia, compensatory activation of gluconeogenesis from FA or for the evaluation of endogenous intoxication.