Changes in serum concentration of a serum amyloid P-like pentraxin in Atlantic salmon, Salmo salar L., during infection and inflammation

A serum amyloid P-like pentraxin has been isolated from Atlantic salmon, Salmo salar L., based on its calcium dependent binding to agarose, The subunits of similar to 37 kDa were all glycosylated and when covalently linked together formed a pentamer with disulphide bonds between all subunits. A specific rabbit antiserum raised against the pentameric form was used to follow changes in serum levels of the salmon pentraxin during infection with Aeromonas salimonicida and inflammation induced by Escherichia coli LPS or killed ii. salmonicida. The salmon pentraxin level in normal serum was in the range similar to 50-300 mu g/ml. Unlike pentraxins from other species, the salmon pentraxin showed only moderate but significant increases or decreases in response to E. coli LPS or A. salmonicida infection, respectively. Although pentraxins and pentraxin-like proteins are evolutionary conserved, not all pentraxins are acute phase responders suggesting that their most ancestral function(s) are not related to acute phase induction. (C) 1999 Elsevier Science Ltd. All rights reserved.