The effect of nitrous oxide on S-adenosylmethionine levels in mouse brain.
Mice were exposed to nitrous oxide (50%) for up to 24 h and S-adenosylmethionine (SAMe) levels measured in corpus striatum and cerebellum, areas with high and low catecholamine turnover rates, respectively. After 4 h, levels were 21 and 8% and after 6 h, 33 and 14% lower than controls in striatum and cerebellum, respectively. Thus, the effect was more pronounced in corpus striatum, the area with the presumed higher rate of catecholamine O-methylation. With continued exposure to nitrous oxide SAMe concentrations in the two areas returned to nearly normal at 24 h. The observation that levels did not continue to decline, and even returned towards control levels, while animals were still in the presence of the gas suggests that a mechanism other than that of methionine synthase inhibition may have been responsible for the initial effect. Alternatively, some other source of SAMe may have become available to compensate for the inhibition of the enzyme.
Department of Pharmacology, Baylor College of Dentistry, Dallas, Texas 75246.
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Dorris
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002531:Cerebellum / Q000187:drug effects / Q000201:enzymology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009609:Nitrous Oxide / Q000494:pharmacology*; D012436:S-Adenosylmethionine / Q000378:metabolism*
D012436:S-Adenosylmethionine; D009609:Nitrous Oxide