Methanol toxicity

All patients with methanol toxicity should be given folic acid 50 milligrams intravenously every 4 hours to increase the metabolism of formic acid. In ethylene glycol ingestion, folate, thiamine and pyri-doxine should all be administered, to enhance the metabolism of the poison to non-toxic products, and minimize oxalic acid production. Calcium supplements are required for symptomatic hypocalcaemia. 

Animal species show great variability in mean lethal doses of methanol. The special susceptibility of humans to methanol toxicity is probably due to folate-dependent metabolism to formate and not to methanol itself or to formaldehyde, the intermediate metabolite. 

Acid). The scientific view on this issue is that normal aspartame consumption levels are much too low to have a methanol toxic effect. 

Medinsky, M.A., and D.C. Dorman. 1995. Recent developments in methanol toxicity. Toxicol. Lett. 82-83 707-711. 

Place the desired amount of Dowex 50W x 8 H+ form (100-200 mesh from Aldrich) according to the relevant protocol and wash with two column volumes of HPLC grade methanol (toxic, flammable) followed by five column volumes of distilled water (the pH should be about 7). 

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. 

One of the failings of cell culture in predictive toxicology is that some examples of toxicity are multi-organ in nature. Methanol toxicity, for example, occurs when the methanol is oxidized in the liver to formate. The formate is transported by the blood to the retina and CNS where it produces its characteristic effects of blindness and brain damage. To model methanol toxicity in cell culture would require co-cultures of liver and retinal cells. Co-cultures are technically difficult, and it would be very difficult to predict which multiple cell types are needed in a co-culture to detect a previously unknown toxicity. It requires an intact organism to do this. 

Methanol toxicity Uremia of renal failure Ketoacidoses Diabetes meUitus Ethyl alcohol toxicity Starvation Paraldehyde toxicity Isoniazid or iron toxicity, also ischemia Lactic acidosis Ethylene glycol toxicity... 

Agency for Toxic Substances and Disease Registry, Methanol Toxicity, TSDR Case Studies in Environmental Medicine, April 1997. 

Ryania. A genus of tropical American shrubs and trees belonging to the Flacourtiaceae family. The wood of various species is insecticidal. Oround stem wood of Ryanie speciosa Vahl., Flacourtiaceae is employed in the commercial insecticide formulations Ryanex, Ryanicide (formerly). See Polkers et al., U.S. pat. 2,400,295 (1946 to Merck Co.) Pepper, Carruth, J. Econ, Entomol 38, 59 (1945) Heal, Agr. Chem. 4, 37 (May. 1949). Insecticidal components such as ryanodine, g.v., are extractable by water, chloroform, or methanol. Toxicity data Kuna, Heal, J. Pharmacol Exp. Then 93, 407 (1948). 

U.S. Department of Health and Human Services. Methanol Toxicity. American Family PhyAician (January 1993) 163 171. 

Because of the methanol toxicity to humans, the handwashes were done by shaking the hands with ethanol Instead of methanol. However, the colorimetric reaction when done In ethanol is not the same as with methanol. The color reaction Is only about 1/5 as sensitive, and, further, decomposition occurs somewhere In the process. For these reasons considerable care was taken to keep the ethanol solutions of carbaryl in the dark and cooled with ice. They were also analyzed as quickly as possible after the field work. 

In 2000, the FDA approved the drug fomepizole, marketed under the name Antizol, for the treatment of methanol poisoning. Fomepizole (C4H6N2) has an affinity for ADH approximately 8000 times that of methanol and is used to treat methanol toxicity without the intoxication and CNS depression caused by ethanol. Dialysis is still used to remove methanol from the blood. 

Methanol is used to power some mass-transit vehicles. When ingested, it is converted to formic acid, the substance responsible for methanols toxic and potentially deadly effects. 

The removal and use of one-carbon units from folate Single-carbon units are removed from folate by a number of reactions. The enzyme 10-formylTHF dehydrogenase provides a mechanism for disposing of excess one-carbon units as carbon dioxide. (Folate administration to animals enhances the conversion of ingested methanol and formate to carbon dioxide, diminishing methanol toxicity.) Additionally, singlecarbon units from 10-formylTHF are used for the biosynthesis of purines (Figure 2). 

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