Influences Of Aeromonas Salmonicida Lipopolysaccharide, Prednisolone And Water Temperature On Plasma Protein Composition In Salmonids

To further characterize the putative role of constitutive and inducible plasma proteins in innate resistance to furunculosis, the present authors compared the alterations in profiles of plasma proteins in resistant and susceptible salmonids, i.e. rainbow trout, Oncorhynchus mykiss (Walbaum), and brook trout, Salvelinus fontinalis (Mitchill), respectively Rainbow trout were injected with prednisolone acetate and exposed to higher water temperature (18 degrees C versus 10 degrees C), or injected with purified lipopolysaccharide (LPS) from a virulent strain of Aeromonas salmonicida, and plasma components were examined by two-dimensional polyacrylamide electrophoresis. Two days after A. salmonicida LPS exposure, rainbow trout had a four- to five-fold increase in concentrations of plasma proteins composed of p48, p19 and p16 subunits, and a significant decrease in a 100-kDa protein group. Consistent elevation or depletion of proteins corresponding to previously reported rainbow trout A. salmonicida LPS-binding pentraxins and lectins in plasma were not observed. Brook trout exposed to A. salmonicida LPS did not have any consistent plasma protein changes. There were no significant alterations in major plasma proteins following temperature shock and prednisolone acetate administration in rainbow trout plasma. These studies demonstrate that rainbow trout with LPS-induced sterile inflammation have few alterations in major plasma proteins or LPS-binding proteins, and do not exhibit the spectrum of acute phase changes induced by inflammation in mammals.