Mitogenic effect of growth hormone and prolactin on chum salmon Oncorhynchus keta leukocytes in vitro

Chum salmon, Oncorhynchus keta, growth hormone and prolactin induced a direct proliferative response on chum salmon peripheral blood leukocytes in vitro. Maximal responses were obtained using 10–100 ng ml−1 of both hormones and were equivalent to the proliferation reference obtained with 100 μg concanavalin A ml−1.