Glutathione is present in all animals. It has been studied since the late 1940s, and probably earlier.
In a 1971 paper, researchers Virginia Minnich and her colleagues explored the synthesis of glutathione (GSH), a crucial antioxidant, in human red blood cells (erythrocytes). They identified two key enzymes responsible for this process: glutamyl cysteine synthetase and glutathione synthetase.
Glutathione is vital for protecting cells from oxidative stress, and its synthesis is essential because it has a turnover rate of about four days in erythrocytes. The study revealed that erythrocytes have a remarkable capacity to produce glutathione, with synthesis rates significantly exceeding the turnover rate. This suggests that red blood cells can quickly replenish their glutathione levels when needed.
The researchers developed simple assays to measure the activity of these enzymes in blood samples from healthy individuals. They found that the levels of these enzymes were consistent across genders and indicated that glutathione synthetase is the rate-limiting step in the overall synthesis of glutathione in erythrocytes.
Additionally, the study highlighted a case of a patient with a deficiency in glutathione synthetase, which led to significantly reduced levels of glutathione in their blood. This deficiency was inherited and could be corrected by adding pure enzyme, demonstrating that the issue was not due to an inhibitor in the patient’s cells.
Overall, this research provided valuable insights into the mechanisms of glutathione synthesis in human erythrocytes, laying the groundwork for understanding its role in cellular protection and potential implications for conditions related to oxidative stress.
… showed an increment in total GSH in hemolysates after incubation with glycine, glutamic acid, cysteine, and ATP, indicating some de novo synthesis of GSH.
The physiological role of GSH synthesis in red cell metabolism remains to be elucidated. The relatively great capacity for GSH synthesis suggests that this pathway may be important in protecting cells against oxidative stress.
Reference
Glutathione biosynthesis in human erythrocytes, dentification of the enzymes of glutathione synthesis in hemolysates. 1971, V Minnich, M B Smith, M J Brauner, P W Majerus https://pmc.ncbi.nlm.nih.gov/articles/PMC291957/