title: Long-term ultrastructural indices of lead intoxication in pulmonary tissue of the rat.
abstract: In the present research long-term pulmonary toxicity of lead was investigated in rats treated by intraperitoneal administration of lead acetate for three consecutive days (25 mg/kg per day). Five weeks after treatment average lead content in the whole blood was 0.41 μg/dL ± 0.05, in the lung homogenates it measured 3.35 μg/g ± 0.54, as compared to the control values of 0.13 ± 0.07 μg/dL and 1.03 μg/g ± 0.59, respectively. X-ray microanalysis of lung specimens displayed lead localized mainly within type II pneumocytes and macrophages. At the ultrastructural level the effects of lead toxicity were found in lung capillaries, interstitium, epithelial cells, and alveolar lining. Alveolar septa showed intense fibrosis, consisting of collagen, elastin, and fibroblasts. Thinned alveolar septa had emphysematous tissue with some revealing signs of angiogenesis. Type II pneumocytes contained lamellar bodies with features of laminar destruction. Fragments of the surfactant layer were often detached from the alveolar epithelium. These findings indicate that 5 weeks after exposure, lead provokes reconstruction of the alveolar septa including fibrosis and emphysematous changes in the lung tissue.
authors.affiliation: Laboratory of Respiratory Reflexes, Polish Academy of Sciences Mossakowski Medical Research Centre, 02-106 Warsaw, 5 Pawińskiego Street, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kaczyńska
authors.forename: Michał
authors.initials: M
authors.lastname: Walski
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Szereda-Przestaszewska
mesh_terms: D056809:Alveolar Epithelial Cells / Q000737:chemistry; D000818:Animals; D004195:Disease Models, Animal; D007854:Lead / Q000633:toxicity*; D007855:Lead Poisoning / Q000473:pathology*; D008168:Lung / Q000473:pathology*; D008264:Macrophages / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D051381:Rats; D013052:Spectrometry, X-Ray Emission
chemical_list: D007854:Lead