The effects of paraquat on neonatal rat lung: a histological and biochemical study

The effects of paraquat on morphological, histological, and biochemical parameters in neonatal rat lung were studied. One-day-old rat pups were injected (IP) with 25 mg paraquat per kg body weight and sacrificed after 24 hr. At the end of the experimental period, the body weight in control and herbicide-treated animals slightly increased and decreased, respectively. The lung weight in the paraquat group was not significantly lower than those of the control. Histologically, the lungs from the paraquat group showed an increase in the thickness of the alveolar wall with much intra-alveolar infiltration of cells and cell debris. In the paraquat-treated group, while the total lung protein increased by about 18%, the enzyme phosphatidic acid phosphatase activity was reduced nearly 30%. These results indicate that paraquat induces both histological and biochemical changes in the neonatal rat lung.