Effect of Cyclophosphamide and High Dose Methylprednisolone on Paraquat Poisoned Rats

ABSTRACT

BACKGROUND: Paraquat(PQ) is used widely all over the world for its excellent effect as a herbicide. But its mortality rate is known to be very high, because there is no effective therapeutic modality. Recently, surprising improvement in survival rate was reported using the cyclophosphamide & methylprednisolone pulse therapy in paraquat poisoning. However, this report was not based upon animal study, we designed this experiment to confirm the therapeutic effect. METHODS: Under the halothane anesthesia, paraquat dichloride 40 mg/kg was injected intraperitoneally to 18 Sprague-Dawley rats. Two hours later, cyclophsphamide 40 mg/kg IP and methylprednisolone 62.5 mg/kg IM were injected in the treatment group(n=9). After 24 hours, we examined serum creatinine levels and pathologic findings of lung stained with hematoxylin-eosin and Masson's trichrome. And 72 hour mortality was compared between 2 groups(5 rats respectively). RESULTS: There were no statistical differences between the treatment group and control group in serum creatinine level, degree of lung injury, and survival rates. CONCLUSION: Cyclophosphamide and high dose methylprednisolone combination therapy did not decrease pulmonary toxicity and mortality of paraquat poisoned rats. Further animal studies using various doses and administrative methods of above medications are necessary to demonstrate their effects.