title: Subchronic inhalation exposure of dearomatized white spirit and C10-C11 isoparaffinic hydrocarbon in Sprague-Dawley rats.
abstract: Groups of 35 male and 35 female Sprague-Dawley rats were exposed to either Dearomatized White Spirit (DAWS) vapor at concentrations of 1.97 and 5.61 g/m3 or C10-C11 Isoparaffinic Hydrocarbon (IPH) vapor at concentrations of 1.91 and 5.62 g/m3. These concentrations were targeted for the recommended occupational exposure limits and three times that value, respectively. Exposures were 6 hr-day, 5 days/week for 12 weeks. Following Weeks 4, 8, and 12 of exposure, a total of 10, 10, and 15 rats, respectively, from each group were sacrificed. Clinical chemistry and hematology parameters were measured in blood samples taken immediately prior to sacrifice, and selected organs were removed and weighted. Twenty-three organs and tissues from each animal were examined microscopically. There were no deaths during the course of this study related to either DAWS or IPH. Mean body weights were significantly lower than controls in male rats following exposure to 5.61 g/m3 DAWS, and 5.62 or 1.91 g/m3 IPH. Body weights were not affected in females. The primary effects from DAWS or IPH exposure were observed in the kidneys of male rats only from both exposure groups beginning at Week 4. Evidence of mild tubular toxicity, such as regenerative tubular epithelia and dilated tubules containing proteinaceous casts, was observed at the corticomedullary junction. The incidence and severity appeared to increase with increasing concentration and exposure duration. There were scattered instances of statistically significant increases in liver and kidney weights in both males and females. With the exception of the mild male rat tubular nephrotoxicity, other significant toxic effects were not observed at levels tested.
mesh_terms: D000473:Alkanes / Q000633:toxicity*; D000818:Animals; D001769:Blood / Q000187:drug effects; D001774:Blood Chemical Analysis; D001835:Body Weight / Q000187:drug effects; D005260:Female; D006838:Hydrocarbons / Q000633:toxicity*; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012997:Solvents / Q000633:toxicity*; D014835:Volatilization
chemical_list: D000473:Alkanes; D006838:Hydrocarbons; D012997:Solvents; C013089:ligroin