71914-80-2

S-Adenosyl-L-methionine (Ademetionine) is involved in three main metabolic pathways: 1) methylation, as the principal source of methyl groups in the body; 2) transsulfuration, S-Adenosyl-L-methionine forms S-Adenosylhomocysteine (SAH) and then converted to homocysteine (Hcy) which can be converted to cystathionine then to cysteine and the sulfate (SO4) donated to other metabolic intermediates; and 3) aminopropylation, as S-Adenosyl-L-methionine plays an important role in the synthesis of polyamines which can eventually form and recycle methionine.
In vitro studies using human articular chondrocytes have shown S-Adenosyl-L-methionine-induced increases in proteoglycan synthesis and proliferation rates in rabbits.

Mice lacking methionine adenosyltransferase 1a (Mat1a) have reduced hepatic S-Adenosyl-L-methionine levels and develop oxidative stress, steatohepatitis, and hepatocellular carcinoma (HCC). However, injury and HCC also occur if hepatic S-Adenosyl-L-methionine level is excessive chronically. Thus a normal hepatic S-Adenosyl-L-methionine level is necessary to maintain liver health and prevent injury and HCC.