Objective: To assess Microcystin LR (MCLR)-induced acute toxic effects in male Sprague-Dawley rats.
Methods: The rats were injected with MCLR intraperitoneally in different doses for different days. The organs and serum with rats were collected at 1 and 7 days after injection, and 7 days after the final injection (total 14 days). Pathological and enzymatic changes were observed.
Results: The rats injected with 122 microg/kg MCLR showed myocardial cells damage including pyknosis, plasma dissolve and myofibrilla (pls check with dictionary) necrosis in the heart muscles after 24 hours. At the same time, the activities of serum glutamate-oxaloacetate transaminase (GOT), lactate dehydrogenase (LDH) and creatine phosphonase (CPK) were higher than these in the other groups (P < 0.01). The kidney was also damaged, kidney cell degeneration, and the increase of blood creatine (BCr) and blood urea nitrogen (BUN) were also seen. In liver pathological study, liver cell hemorrhage, degeneration and/or necrosis was observed. In serum the activities of glutamate-pyruvate transaminase (GPT), alkaline phosphatase (LDH) and GOT were higher than these in the other groups (P < 0.01).
Conclusion: These results suggested that MCLR can injure the heart, kidney and the liver in SD rats, and there is a dose-response relationship between MCLR and the toxic effect.