Ontogeny of the enzymes related to γ-glutamyl cycle in the human fetal system.

Measurements have been made of the enzymes associated with γ - glutamyl cycle viz, γ-glutamyl transpeptidase, γ-glutamyl cysteine synthetase, and 5-oxoprolinase in human fetal brain, liver and kidney over 12-36 weeks of gestation. γ-Glutamyl transpeptidase activity increases gradually with age. γ-Glutamyl cysteine synthetase and 5-oxoprolinase show biphasic pattern of development in human fetal brain. The data presented in this communication may indicate a relationship between γ-glutamyl cycle and amino acid transport.