JPEN J Parenter Enteral Nutr. 1998 Nov-Dec;22(6):393-8. doi: 10.1177/0148607198022006393.


Glycine consists of a single carbon molecule attached to an amino and a carboxyl group. Its small size helps it to function as a flexible link in proteins and allows for the formation of helices, an extracellular signaling molecule, recognition sites on cell membranes and enzymes, a modifier of molecular activity via conjugation and glycine extension of hormone precursors, and an osmoprotectant. There is substantial experimental evidence that free glycine may have a role in protecting tissues against insults such as ischemia, hypoxia, and reperfusion. This impressive catalogue of functions makes an interesting contrast with glycine's perceived metabolic role as a nonessential amino acid. Glycine interconverts with serine to provide a mechanism for the transfer of activated one-carbon groups. Glycine has just been viewed as a convenient source of nitrogen to add to solutions of nutrients. Although this may have unexpected benefits when such solutions are used in clinical practice, it does raise the specter of a possible confounding effect in experiments when glycine is added to control solutions to make them isonitrogenous.

Publication types

  • Review

MeSH terms

  • Animals
  • Cytoprotection
  • Glycine / metabolism
  • Glycine / physiology*
  • Glycine / therapeutic use
  • Humans
  • Liver / metabolism


  • Glycine