The effects of pure microcystin LR and biomass of blue-green algae on selected immunological indices of carp (Cyprinus carpio L.) and silver carp (Hypophthalmichthys molitrix Val.)

The aim of this work was to study the effects of Microcystin LR and biomass of blue-green algae with known amount of Microcystin LR on immunological indices in juvenile carp and silver carp. The pure Microcystin LR or biomass of blue-green algae with a known amount of Microcystin LR was applied to experimental fish. Pure Microcystin LR in the dose of 400 mu g per kg of body mass was administered intraperitoneally, the biomass per os to carp and per anus to silver carp. The volume of Microcystin LR in single doses was 3, 300, 600 and 1200 pg per kg of body mass. After 24 and 48 h blood was collected from fish by cardiac punction. The following immunological indices were determined: total leukocytes, leukocrit, differential leukocyte count, numbers of sIg+ and T cytotoxic lymphocytes and occasionally numbers of NK cells by means FITC protein A, HP lectin and monoclonal antibody anti CD 11b and phagocyte activity by luminol enhanced chemiluminiscence. Decrease of total leukocyte count and leukocrit were characteristic changes due to the treatment. With carp this decrease occurred mainly in lymphocytes (Tcytotoxic and sIg+ cells), with silver carp mainly in myelocytes (neutrophilic myelocytes and metamyelocytes). With carp the most remarkable changes were observed after oral administration of biomass of blue-green algae containing Microcystin LR in the dose of 1200 mu g per kg of body mass. On the other hand, minor changes were observed after i.p. administration of pure toxin. These changes correspond with changes in phagocytic activity of cells: minor changes were detected in carp, while in silver carp the decrease of myelocyte cells brought a major decrease of phagocytic activity.