Effect of prolactin, in vivo and in vitro, upon heterophil phagocytic function in the ring dove (Streptopelia risoria).

The purpose of this study was to investigate the effects of prolactin, both in vitro and in vivo, upon heterophil phagocytic activity of the ring dove, Streptopelia risoria. In vitro incubation of heterophils with either 0.1 or 100 micrograms/mL of ovine prolactin for 2 h-significantly increased both latex bead phagocytosis and Nitroblue tetrazolium (NBT) reduction, an index of phagocytic metabolic activity. Ring doves given antigen demonstrated an increase in latex bead phagocytosis and NBT reduction. The greatest increase in both of these parameters was observed in those birds which possessed elevated plasma prolactin concentrations, either through exogenous administration or naturally through being in the later stages of incubation. These results suggest that during the incubation period of the avian breeding cycle there is an increase in phagocytic activity which is a direct consequence of the elevation shown by these birds in the concentration of plasma prolactin.