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

Treatment	Bronchial region	Blood vessels	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