Impaired Natural Killer Cell Activity in Iron-Deficient Rat Pups

Natural killer (NK) cell activity was studied in iron-deficient rat pups. Pregnant dams were fed diets containing 6, 10 or 250 ppm Fe ad libitum from d 1 of gestation through d 21 of lactation. Two days post parturition litters were adjusted to seven pups each, and on d 17 the pups were injected intraperitoneally with 5 × 105 plaque-forming units of vaccinia virus. Following a 4-d incubation period, spleens were removed and the cell suspensions combined with YAC-1 target cells to measure cytolysis in a 4- and 16-h chromium release assay. Hematocrit levels of severe (6 ppm) and moderately (10 ppm) iron-deficient rat pups were significantly lower than that of controls. Similarly, body weight and spleen weights were significantly lower in irondeficient pups than in control pups. Iron deficiency significantly impaired spleen NK cell activity when measured by two different effector:target ratios and assay time periods.