ABSTRACT
Anoxic hepatocellular injury is characterized by a loss of oxidative phosphoylation with rapid depletion of cellular adenosine triphosphate (ATP). In addition, the comparable cytoprotection provided by the tripeptide, glutathione, in proximal tubule cells during anoxia was also attributed to release of glycine from the carboxyl terminal end of glutathione. This chapter demonstrates that glycine cytoprotection in rat hepatocyte suspensions is associated with an inhibition of total cellular proteolysis. It demonstrates that glycine was cytoprotective in rat hepatocytes during ATP depletion by potassium cyanide. The chapter evaluates the effect of glycine on a number of putative mechanisms thought to cause lethal cell injury such as intracellular ATP depletion, loss of glutathione, changes in cytosolic pH, and protein synthesis. Negative feedback control by amino acids on both lysosomal and nonlysosomal proteolysis could serve to increase the availibility of amino acids by proteolytic processes for gluconeogenesis in the liver during periods of starvation or amino acid deprivation.
