Synopsis. S-Adenosyl-L-Methionine, better known as (SAMe), is the active methionine, formed as a result of ATP interaction with the essential aminoacid methionine of the gluconeogenics group, whose main metabolic function is the providing of methyl groups, so that they take part in diverse transmethylation reactions [1]. This is a physiological molecule, present in all the organism's tissues and fluids. It has a fundamental importance because it intervenes in numerous biochemical reactions. Among its main metabolic functions is included the different molecules methylation, in which it participates in numerous enzymatic transmethylation reactions, influencing this way on the synthesis, activation and/or the metabolism of diverse compounds such as hormones, neurotransmiters, nucleic acids, proteins and phospholipids, among others [1, 2].
In ultimate instance, the (SAMe) happens to be a metabolite in the transsulphuration chain of the methionine metabolism, the said metabolic process takes place in the liver, for which this organ uses more than 70 per cent of the methionine intaken through feeding [3]. The required enzyme for the S-Adenosyl-L-Methionine synthesis is the (SAMe) synthetase, that catalyzes the transport of half of the Adenosyl of the Adenosine Triphosphate (ATP).
By the sulphur atom in Methionine, the resulting sulphonic compound (SAMe) is the active methylated agent that donates its methyl group to a diversity of receiveing molecules responsible for the formation of polyamines, cisteine, glutamine, taurine and other more methylated molecules. Consequently, the majority of methylation molecules involve (SAMe) as a methyl donor, so that if in this process some gearwork gets blocked, the endogenous synthesis of these nutrients will be surely subnormal [4].
S-Adenosyl-L-Methionine in Cellular Biochemistry. As a methyl group donor, (SAMe) acts in many transmethylation reactions, including those involved in phospholipid biosynthesis, which play various important roles inside the cellular membrane and that can be summarized in the following manner: a) they influence on the enzymatic cellular regulation; b) on the membrane fluidity, and c) on the cellular bioelectrical activity. The loss of these capabilities in brain cells of old animals were associated with both the loss of dopaminergic and beta-andrenergic joining points, and changes in the composition of the cell membrane also [5].
With the exogenous administering of (SAMe), normal levels of phospholipids are maintained, and the enzymatic activity is restored, leading toward a normalization of the metabolic process inside the cell. It's also supposed that the activation of enzymes that affect