Table 1 Morphological evaluation of the rat lungs after 2 hours perfusion and inhalation exposure to Ir-UFP, using lung sections and HE- or toluidine blue staining The regions investigated included the bronchial segment, the blood vessels and the alveolar region

Control

Sub epithelial round cell filtration; interstitial dilation

Interstitial dilation

Small alveolar dilation in periphery

Hydrogen peroxide

Desquamation of epithelial layer, partially destruction of sub epithelial structure

Moderate to severe dilation

Histamine Perfusate

Sub epithelial round cell filtration; interstitial dilation

Moderate to severe interstitial dilation

Alveolar dilation in periphery

Histamine (Bolus)

Sub epithelial round cell filtration; interstitial dilation

Moderate to severe interstitial dilation

Focal alveolar dilation, oedematous fluid in alveolar lumen