Serum protein changes in brown trout (Salmo trutta L.) after single injections of soluble and cellular antigens

Brown trout sera were examined by cellulose acetate (CAE) and polyacrylamide electrophoresis (PAE) and the protein concentrations measured by the Lowry method, before and after stimulation with haemocyanin, horse serum, Salmonella typhi‘H’ and human group ‘O’ erythrocytes. Uninjected fish contained 5.l1±0.71 g protein/100 ml. Protein concentration was unaffected by haemocyanin and horse serum but was significantly lowered by S. typhi and human group ‘O’ erythrocytes. Male and female fish gave similar responses. Uninjected and injected fish showed 8 components on CAE and 16 on PAE. Significant differences were found between injected and uninjected control fish and between antigen stimulated and uninjected controls.