Methanol metabolism

Narbad A, MJ Hewlins, AG Callely (1989) C-NMR studies of acetate and methanol metabolism by methylo-trophic Pseudomonas strains. J Gen Microbiol 135 1469-1477. 

Metabolic differences also account for the great species variability in methyl alcohol toxicity with humans and nonhuman primates being uniquely sensitive. (A relatively poor ability to metabolize the methanol-metabolized formate in these species leads to increased blood formate levels and subsequent metabolic acidosis and neuronal toxicity.)... 

What are the metabolic products of ethanol oxidation in the body How does the rate of ethanol metabolism compare to that of methanol metabolism ... 

Inhibiting methanol metabolism. Ethanol, which occupies the dehydrogenase enzymes in preference to methanol, competitively prevents metabolism of methanol to its toxic products. A single oral dose of ethanol 1 ml/kg (as a 50% solution or as the equivalent in gin or whisky) is followed by 0.25 ml/kg/h orally or i.v., aiming to maintain the blood ethanol at about... 

Humans and primates appear particularly sensitive to methanol toxicity when compared to rats. This is attributed to the slower rate of conversion in humans of the formate metabolite via tetrahydrofolate. This step in methanol metabolism occurs in rats at a rate 2.5 times that observed in humans. 

Tephly, T.R., and K.E. McMartin. Methanol Metabolism and Toxicity in Aspartame. In Physiology and Biochemistry, edited by L.D. Stegink and L.J. Filer, Jr., in. New York Marcel Dekker, 1984. 

In the conditions discussed above (diabetic ketoacidosis, lactic acidosis, uremia, and ingestion of salicylate, ethylene glycol, or methanol) metabolic acidosis is associated with an increased anion gap. In the face of excess metabolic acids, bicarbonate is depleted in the process of buffering excess hydrogen ions. Provided that the renal functions is normal, the kidney attempts to compensate by secreting an acid urine and retaining bicarbonate. 

The treatment of methanol poisoning involves firstly the administration of an antidote, ethanol, which blocks metabolism. Ethanol competes with methanol for alcohol dehydrogenase as the enzyme has a greater affinity for ethanol. Methanol metabolism can be reduced by as much as 90% by an equimolar dose of ethanol and the half-life becomes extended to 46 h. 4-Methylpyrazole, which also binds to alcohol dehydrogenase, has been used successfully in monkeys to treat methanol poisoning, as has folic acid. 

Y., and Veenhuis, M. (2006) The significance of peroxisomes in methanol metabolism in methylotrophic... 

First aid for liquid methanol contact with eyes or skin is immediate water flush for 15 min. For vapor aq)osure and inhalation, the victim should be removed to fresh air and gven artificial respiration if needed. If in stion is suspected, a physician should be called and treatment should be initiated as quickly as possible. Effective measures for conscious patients include inducing vomiting [6,17], orally taking 3040 ml ethanol to delay methanol metabolism [6,49], and orally taking 510 g of sodium bicarbonate (baking soda) in a glass of water every hour to combat acidosis [75]. 

The methanol molecule is smaller than carbon dioxide and penetrates most plant tissues quickly for rapid metabolism. As a plant source of carbon, methanol is a liquid concentrate 1 cc methanol provides the equivalent fixed-carbon substrate of over 2,000,000 cc of ambient air. Methanol absorbed by foliage is metabolized to carbon dioxide, amino acids, sugars, and other structural components. Two major paths of methanol metabolism are the internal production of carbon dioxide that is then utilized in photosynthesis and the incorporation of methanol as a fixed source of carbon. Briefly stated in field terms, methanol treatments are a means of placing carbon directly into the foliage. Hi li t intensity is necessary to drive photosynthesis at the rates necessary to process the high internal levels of carbon dioxide presented by methanol. Serine formation and carbon dioxide fixation by photosynthesis may lead to the production of su. Increases of su concentration in the presence of moisture lead to increased turgidity. 

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