Abstract
Characteristics of natural killer-like cells (NK-like cells) in carp (Cyprinus carpio) were studied by 51Cr-release assay. Among cells examined, K562 cells (human erythroleukemic cells) were found to be the most suitable as target cells for NK assay in carp. Pre-incubation of the leucocytes from head kidney and peripheral blood enhanced NK activity. Leucocytes from the head kidney and kidney showed the highest NK activity and those from peripheral blood, thymus and spleen followed in the order. The cold target inhibition test indicated that carp NK-like cells consist of more than one population for target recognition.