The presence of (+)-S-adenosyl-L-methionine in the rat brain and its lack of effect on phenylethanolamine N-methyltransferase activity.
(+)-S-Adenosyl-L-methionine [(+)-SAM] was isolated from rat brain and was quantified by HPLC followed by UV spectrophotometric measurements and by 1H-NMR. Its estimated ratio in brain is 3% of total SAM. Because of its commercial unavailability, (+)-SAM was also prepared from chemically synthesized SAM by separation of the two diastereoisomers on a preparative reverse-phase Nucleosil C8 column. The (+) diastereoisomer thus obtained was then assayed in vitro both as an inhibitor and a substrate of phenylethanolamine N-methyltransferase. Enzymatic activity was measured by HPLC analysis. It was shown that (+)-SAM has no effect on phenylethanolamine N-methyltransferase activity; therefore, it is unlikely that (+)-SAM plays any possible role in regulation of adrenaline synthesis in the brain.
Beaudouin
C
C
Laboratoire de Neuropharmacologie, Faculté de Pharmacie, Université Claude Bernard, Lyon, France.
Haurat
G
G
Laffitte
J A
JA
Renaud
B
B
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010625:Phenylethanolamine N-Methyltransferase / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012436:S-Adenosylmethionine / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D013237:Stereoisomerism; D014466:Ultraviolet Rays
D012436:S-Adenosylmethionine; D010625:Phenylethanolamine N-Methyltransferase