ABSTRACT A method for obtaining primary cultures of epithelial cells from rainbow trout gills is described. The yield of cells from approximately 1.5g wet mass of tissue was 218×106±12×106 cells with a viability defined by eosin exclusion of 80±6%. Cells were seeded in culture dishes and grown in Leibowitz L-15 medium supplemented with 5 % foetal bovine serum. Attachment efficiency after 24h was 35±6%. The cells appeared confluent 10–12 days after seeding and exhibited surface structures similar to those seen on respiratory epithelial cells of trout gills in vivo. Growth rate, [3H]thymidine incorporation and attachment efficiency were used to evaluate culture conditions. Epidermal growth factor, insulin, transferrin, hydrocortisone, laminin and collagen did not improve growth and attachment. Similarly, coating the culture dishes with rat tail collagen, trout skin extract, laminin or a mixture of human basement membrane proteins (Matrigel) failed to improve attachment. It is concluded that the cells in culture are respiratory epithelial cells and that this culture system could provide a valuable new approach for studying the physiology of these cells.

Cadmium transfer through and the retention of metal in perfused gills from rainbow trout (Salmo gairdneri) has been studied in the presence of two detergents, LAS (linear alkylaryl sulphonate) and NP-10EO (nonylphenol ethoxylate). Accordingly, the effects of the metal and the surfactants on gill viability (vascular resistance, oxygen diffusion capacity, sodium net flux) was measured. Cd had no effect on gill viability either at 0.008 or at 9.0 μmol/liter during a 60-min perfusion period. The viability of the gills deteriorated markedly during 60 min of exposure to 100 μmol/liter LAS and to NP-10EO, or to a mixture of 100 μmol/liter surfactant + 8.1–8.3 μmol/liter Cd. LAS, 100 μmol/liter, reduced Cd transfer, whereas NP-10EO had no effect. NP-10EO increased Cd retention in gill tissue. LAS more than doubled Cd transfer through the gills when tested in concentrations expected to be found in a polluted recipient (0.9 μg/liter Cd + 0.05 mg/liter LAS). NP-10EO had no effect on the transfer when tested under these environmentally relevant conditions.