IMMUNOCYTOCHEMICAL AND RADIOIMMUNOASSAY STUDIES ON NORTHERN PIKE (ESOX-LUCIUS) AND WALLEYE (STIZOSTEDION-VITREUM) GROWTH-HORMONE

Blood and pituitary samples were collected from northern pike and wall eye for immunocytological and radioimmunological measurements employin g an antiserum to chum salmon growth hormone. The peroxidase-antiperox idase immunohistochemical method showed that anti-chum salmon GH immun oreactive cells were localized to the acidophil cells of the caudal pa rs distalis of the adenohypophysis in both species. Radioimmunoassays indicated that there was no observable difference between inhibition c urves obtained using purified chum salmon GH and plasma from northern pike. However, plasma from walleye produced statistically different in hibition curves. These results are discussed with respect to phylogene tic differences and their usefulness as screening techniques for trans genic fish injected with salmon GH genes.