Glutathione Synthesis and Turnover in the Human Erythrocyte Journal of Biological Chemistry In RBCs, NADPH are produced exclusively via HMP shunt by the action of G6PD and are responsible to maintain membrane integrity preventing premature destruction. That is why G6PD deficient RBCs are Heinz bodies are small clumps of damaged hemoglobin found inside red blood cells. They form due to oxidative stress and are often seen in conditions like G6PD deficiency. Their presence can indicate Simplify your Glutathione Measurements Arbor Assays