Phagocytosis and lysozyme activity in granulocytes from iron-deficient rat dams and pups

The effect of dietary iron deficiency during gestation and lactation on phagocyte function in rat dams and pups was investigated. Pregnant rats were fed ad libitum diets containing 7, 10 or 250 ppm iron throughout gestation and until day 17 of lactation when dams and their litters (7 pups) were sacrificed. Phagocytosis was measured by the nitroblue tetrazolium (NBT) dye reduction test. Lysozyme activity was measured in granulocytes separated from peripheral blood. A significant increase in percent phagocytes in whole blood in the 7 ppm iron pups was observed. Total white blood cell (WBC) counts were similar among groups. The 7 ppm iron pups had markedly decreased NBT reduction (per 10⁸ phagocytes). On a per ml of blood basis, there were no differences in NBT reduction among groups. Plasma activities of the two granulocyte enzymes measured, lysozyme and peroxidase, were significantly increased in 7 ppm iron pups. It was shown that this increase in plasma lysozyme activity was not due to an increased concentration of lysozyme in granulocytes.