EXOTOXIN-INDUCED CONSUMPTIVE COAGULOPATHY IN ATLANTIC SALMON, SALMO-SALAR L - INHIBITORY EFFECTS OF EXOGENOUS ANTITHROMBIN AND ALPHA(2)-MACROGLOBULIN ON AEROMONAS-SALMONICIDA SERINE-PROTEASE

Consumptive coagulopathy was induced within 4 h in Atlantic salmon, Sa lmo salar L., by injecting purified serine protease from Aeromonas sal monicida into the dorsal aorta. Pretreatment with a bolus intravascula r injection of (human) antithrombin (AT) or (bovine) alpha2-macroglobu lin (alpha2M) just prior to injection of the protease alleviated the i n vivo pro-coagulant effects of the enzyme, but could not hinder the d evelopment of consumptive coagulopathy. In fish receiving only saline as pretreatment, the coagulopathy was evident even after 28 h, but the fish were not overtly sick. The addition of the exogenous inhibitors increased the fish's natural protection against the bacterial exotoxin , suggesting that both AT and alpha2M are of importance for the outcom e of the pathologic process. Results further indicate that while AT in vivo was mainly directed against generated thrombin and activated coa gulation factor X (FX(a)), alpha2M inhibited the protease directly.