title: Distribution, localization, and pulmonary effects of yttrium chloride following intratracheal instillation into the rat.
abstract: Metabolic behavior and pulmonary toxicity of yttrium chloride (YCl3) deposited in the lung was investigated. Yttrium chloride was instilled intratracheally into rats and the time-course and dose-related changes in distribution of Y between lung tissue and bronchoalveolar lavage fluid (BALF) and pulmonary inflammatory responses were investigated. Pulmonary clearance of Y was very slow and the half-life was estimated to be 168 days. Yttrium content in the supernatant of BALF did not exceed 5 micrograms Y/lung even when a dose of 200 micrograms Y/rat was administered, suggesting that the alveolar surface fluid could retain at most 5 micrograms Y. On the other hand, Y content in the pellet of BALF changed with the number of macrophages retrieved in BALF in both time-course and dose-response experiments. Transmission electron microscopy and X-ray microanalysis suggested that Y was localized in lysosomes of alveolar and interstitial macrophages, and basement membranes. These results clearly explain the long pulmonary half-life of Y. beta-Glucuronidase activity and calcium and phosphorous contents in the supernatant of BALF increased significantly even at the lowest dose (10 micrograms Y/rat). Comparative dose-effect profiles of lactate dehydrogenase activity in BALF supernatant revealed that 1 mol of YCl3 is equivalent to about one-third mole of cadmium compounds and about 3 mol of zinc oxide in the potency for acute pulmonary toxicity.
authors.affiliation: National Institute for Environmental Studies, Ibaraki, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Hirano
authors.forename: N
authors.initials: N
authors.lastname: Kodama
authors.forename: K
authors.initials: K
authors.lastname: Shibata
authors.forename: K T
authors.initials: KT
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000032:analysis / Q000201:enzymology / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005966:Glucuronidase / Q000378:metabolism; D006207:Half-Life; D007442:Intubation, Intratracheal; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008168:Lung / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure; D008264:Macrophages / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009504:Neutrophils / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D015019:Yttrium / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000633:toxicity
chemical_list: C064782:yttrium chloride; D015019:Yttrium; D007770:L-Lactate Dehydrogenase; D005966:Glucuronidase