Abstract
Homocysteine is a sulphurous amino acid, not present in a diet, but it is a significant intermediate arising in a cycle of transmethylating and transsulphurating reactions, where methionin and cysteine take part. In metabolic cycle methionin-homocysteine activated methionine (S-adenosyl-methionine) acts as a source of methyl groups for plenty of compounds such as nucleic acids, proteins, phospholipids, cholin, etc.
Methylation disturbances lead to disorders of cell growth and differentiation. Transsulphurating reactions of homocysteine také part in the synthesis of glutathione, one of the most important antioxidants.
Hyperhomocysteinemia is connected with an increased occurence of cardiovascular diseases caused by atherosclerosis and thrombosis, especially ischaemic heart disease and cerebrovascular disease, and with hypercoagulable states and thromboembolic disease, as well as.