Cystine: the Preferred Substrate for Optimal Glutathione Synthesis and Immune Enhancement
Hepatic Nitrogen Metabolism: Cysteine from muscle catabolism arrives in the liver in the form of cystine. Enteral feeding of cystine takes advantage of this well-developed metabolic pathway that is also utilized when digesting breast milk which has well documented and indisputable immune enhancing properties.
Antigen Presenting Cells: Prefer cystine for GSH synthesis which is required to initiate the immune response then feed lymphocytes cysteine as an immunoregulatory signal.
Astrocytes: Prefer cystine for GSH synthesis and feed cysteine to neurons to protect against neurodegenerative diseases.