The immunomodulatory effects of levamisole on rainbow trout, Oncorhynchus mykiss.

Abstract

The immunomodulatory effects of levamisole were investigated using rainbow trout, Oncorhynchus mykiss. Fish sampled 5 days after intraperitoneal injection of levamisole showed increased protection against Vibrio anguillarum when a single dose (0.5 mg/kg) was used. Phagocytic activity, chemiluminescence responses and natural killer cell activity in fish treated with levamisole were also increased, compared with those in the saline treated fish. Furthermore, levamisole activated the alternative complement pathway of rainbow trout, although serum bactericidal activities against V. anguillarum were not enhanced by the treatment of levamisole. These results indicate that levamisole has immunomodulatory effects in rainbow trout.