Pathological and biochemical characterizations of microcystin-LR-induced liver and kidney damage in chickens after acute exposure.

Cyanobacteria contains considerable amounts of protein and other nutritive materials and are considered to be high-quality protein source and feed additive for livestock and poultry. However, some species of cyanobacteria are also able to produce toxins, and exposure to these toxins represents health risks to animals. In the present study, pathological changes and biochemical responses were examined in the liver and kidney of the Chongren chicken (Gallus gallus domesticus) after intraperitoneal (i.p.) injection with microcystin-LR (MC-LR) at dose of 5 μg kg (Low dose group, LD group), 10 μg kg (Medium dose group, MD group), and 20 μg kg (High dose group, HD group), respectively. Results revealed that the high dose of MC-LR led to the irreversible liver damage, which was characterized by mononuclear infiltrations，necrotic changes and blood congestion, and obvious recovery of hepatocytes was observed in the low and medium dose groups. Across all groups, the MC-LR-induced injuries in the kidney were prominent since the first hour, and it did not get any better at the end of the experiments. The MC-related detoxification and antioxidant components (GSH, GPX, GST) in the liver made positive responses, which helped to alleviate the cytotoxicity of MC-LR. Our results showed that even at low concentrations of MCs (produced by cyanobacteria), pathological changes (such as necrosis and inflammation) were observed in liver and kidney of birds.