The ministry of Agriculture , Forestry and Fishers of Japan. National Livestock Breeding Center Okazaki Farm, Okazaki, 444-3161 Superoxide production estimated by nitroblue tetrazolium (NBT) reduction was investigated in zymosan-or PMA-stimulated macrophages and heterophils sampled from various sites of the chicks. Moreover, the effects of starvation on the superoxide production and the phagocytic activity of the cells were examined. Superoxide production in each of the two kinds of phagocytes was classified into 4 categories based on density of reduced NBT in their cytoplasm (none, weak, medium and strong). Phagocytic activity of cells was estimated by number of zymosans ingested. In zymosan-and PMA-stimulated heterophils, peripheral blood cells showed a higher incidence of weak density cells and a lower incidence of strong density cells than abodominal cells. In macrophage lineage, the percentages of cells which did not show detectable amount of reduced NBT on visual inspection were significantly higher in alveolar and splenic macrophages than those in monocytes and abdominal cells. On the contrary, incidence of medium and strong density cells in alveolar and splenic macrophages were significantly lower than those in monocytes and abdominal macrophages. These results agreed with the results which indicated that there were differences in phagocytic and microbicidal activity among phagocytes collected from different sites of chicks. The incidences of medium or high density cells decreased following starvation in zymosanand PMA-stimulated abdominal heterophils, peripheral blood heterophils, abdominal macrophages and monocytes. On the contrary, incidences of low density cells were significantly increased in these phagocytes. These results suggested that starvation specifically influences heterophils and macrophages which have high superoxide production activity and that there are heterogeneity as to superoxide production in the phagocytes collected from each site of chicks. In alveolar and splenic macrophages, effect of starvation was not able to detected because most of cells were classified into no density category. Phagocytic activities of monocytes and abdominal, splenic and alveolar macrophages estimated by number of zymosans ingested were not changes by starvation.
