[NADP+ catabolic enzymes in differentiating rabbit erythroid cells]

NADP-glycohydrolase and NADP-pyrophosphates activities were examined during the rabbit erythroid cell differentiation. The former is high in erythroblast lysates, especially in the erythroblast nuclei. As erythroid cell maturation proceeds, the activity of NADP-glycohydrolase decreases. At the first step (erythroblast-reticulocyte transformation), this activity falls down more than by 20 times, whereas at the second step (reticulocyte-erythrocyte transformation) it decreases no more than twice. NADP-glycohydrolase is associated with the stroma of erythroid cells throughout their maturation, being bound with the nucleus in erythroblasts. NADP-pyrophosphatase activity has been detected in reticulocytes and mature cells only. The role of NADP- and NAD-glycohydrolases for characterization of the intracellular metabolic pools is discussed.