Lung morphology in experimental acute paraquat poisoning. SEM observations.

The authors describe the SEM ultrastructural aspects of rat lungs following acute paraquat poisoning. The results obtained confirmed previous TEM observations and suggest an early inhibition of secretory activity in type II alveolar cells. This morphological aspect can be related to the generally known early development of respiratory difficulties following acute paraquat poisoning. The technique employed allows a precise study of alveolar reepithelization in further stages of poisoning. These last observations agree with the hypothesis of reepithelization by type II alveolar cells.