Interrelationships of erythrocyte glutathione peroxidase system enzymes in the fasted Beagle.

Eight adult female Beagles were fasted for 21 days to investigate responses of the erythrocyte glutathione peroxidase system enzymes. Blood samples were collected once a week. Erythrocyte reduced glutathione was maintained within 10% of base-line value. Hexose monophosphate pathway dehydrogenases showed a significant inverse relationship to glutathione reductase (GR) activity. Further, active GR, as a percentage of total GR, increased as hexose monophosphate pathway dehydrogenase activity fell. A similar relationship between these enzymes has been reported in human glucose-6-phosphate dehydrogenase deficiency. Also, glutathione peroxidase showed an inverse linear response to erythrocytic reduced glutathione. Though the responses of this system are complex, they appear interrelated.