title: Decalin-induced nephrotoxicity: light and electron microscopic examination of the effects of oral dosing on the development of kidney lesions in the rat.
abstract: Male and female Fischer 344 rats were given decalin by oral gavage for 5 or 12 consecutive days in order to determine whether oral dosing would result in light microscopically evident renal effects that were comparable to those that have been observed after inhalation exposure. Decalin (in corn oil vehicle) was administered at doses of 0, 0.1, 0.5, 1.0 or 2.0 g/kg body weight to male rats, and 0, 1.0, 1.5, 1.75 or 2.0 g/kg to female rats. Biopsies of the kidneys of selected control and high-dose male rats were taken for examination by electron microscopy. Sections of kidneys from all control and treated rats were examined by light microscopy. The kidneys of all male control rats contained minimal levels of hyaline droplets within the cytoplasm of proximal convoluted tubule (PCT) epithelial cells. Decalin-induced alterations in the kidneys of male rats included an exacerbation of the hyaline droplet/globule levels found in controls and the formation of granular casts in the outer zone of the renal medulla. The exacerbated formation of hyaline droplets was characterized light microscopically by a marked dose-related increase in the number and size of individual droplets/globules and ultrastructurally by a marked increase in the size range of, and the presence of crystalline inclusions in, the PCT epithelial cell phagolysosomal populations. No other ultrastructural alterations occurred that differentiated treated male rats from control males. The formation of granular casts was dose and time related, occurring in 60% of male rats given 0.5 g decalin/kg for 12 days and in 100% of those given 1.0 g decalin/kg for 12 days. Light microscopy revealed no differences between the kidneys of control and decalin-treated female rats, and no hyaline droplets or granular casts were observed in the kidneys of any female rat killed after 5 or 12 days. These results were in agreement with those of inhalation studies and provide additional evidence that the formation of hyaline droplets in response to exposure to volatile hydrocarbons may be unique to the male rat.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D005260:Female; D007674:Kidney Diseases / Q000139:chemically induced* / Q000473:pathology; D007679:Kidney Medulla / Q000473:pathology; D007687:Kidney Tubules, Proximal / Q000473:pathology / Q000648:ultrastructure; D008297:Male; D008853:Microscopy; D008854:Microscopy, Electron; D009281:Naphthalenes / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D009281:Naphthalenes; C007229:decalin