HISTOPATHOLOGICAL, HISTOMETRICAL AND ULTRASTRUCTURAL STUDIES IN PROTECTIVE EFFECTS OF SUPEROXIDE DISMUTASE AGAINST DIFFUSE ALVEOLAR DAMAGE OF THE RATS INDUCED BY PARAQUAT

Histopathological, histometrical and ultrastructural changes in protective effects of recombinant human Cu, Zn-superoxide dismutase (SOD) against diffuse alveolar damage (DAD) of the male rats induced by paraquat were studied. The animals were given a single intraperitoneal injection of 25mg/kg body weight of paraquat, followed by a single intraperitoneal injection of 46, 000U/kg body weight of SOD at 1 and 7 hour after paraquat injection for SOD group. In contrast an equal volume of saline was injected instead of SOD for the control group. Difference in results between SOD and control groups was early and late phase effects. In the early phase effects, pulmonary congestion was suppressed from 2 hours after paraquat injection and edematous swelling of type I alveolar epithelia was significant even 24 hours after paraquat injection in the SOD group. In the late phase effects, proliferative changes of alveolar epithelium and interstitium in the SOD group were decreased. From these results, it is supposed that 1) paraquat-induced DAD is alleviated by SOD treatment which results in a scavenger of the superoxide radical and suppression of secondary inflammation by paraquat injection, and 2) SOD treatment may be an effective treatment for paraquat toxicity.