A comparison of cellular damage elicited in animals receiving doses of UFTiO
normalized to surface area of particle administered per surface area of alveolar epithelium. A comparison of cellular damage elicited in animals receiving doses (0.0313, 0.0625 and 0.125 cm2/cm2) of UFTiO2 and FTiO2 normalized to surface area of particles administered per surface area of alveolar epithelium at 1 day (Panel A), 7 days (Panel B), and 42 days (Panel C) post-exposure. Rats were exposed to various mass doses of UFTiO2 and FTiO2 by intratracheal instillation. Animals were euthanized at 1 day, 7 days, and 42 days post-exposure and bronchoalveolar lavage was performed. Cellular injury was assessed by measuring albumin levels. Control values of albumin levels were 0.073 ± 0.033, 0.084 ± 0.003, 0.098 ± 0.007 mg/ml for 1, 7, and 42 days, respectively. Values are increase in albumin levels above the BALF control and are given as means ± SE of 8 experiments. Linear regression analysis with a 95% confidence interval reveals that, when dose is normalized to surface area of particles administered, responses to UFTiO2 and FTiO2 are not significantly differently.