The effects of cortisol and actinomycin D injections on chloride cells and branchial Na+ -K+ -ATPase in rainbow trout (Salmo gairdneri).

Injections of cortisol, actinomycin D, or combined administration of the hormone and the antibiotic did not effect rainbow trout (Salmo gairdneri) branchial Na+ -K+ -ATPase activity. Numbers of chloride cells also did not change following cortisol and actinomycin D treatment. These results are discussed in light of a similar report concerning Atlantic salmon (Salmo salar).