| Abstract |
To examine the effects of continuous exposure over two generations and the possibility of non-linearities in the dose responses over a wide dose range, dibutyl phthalate (DBP), was administered in the diet at concentrations of 1 ppm (Control), 4, 10, 30, 100, 1,000, and 10,000 ppm to groups (n=17 male and 17 female) of Sprague-Dawley rats over two generations. The F0 generation began exposure as adults and were bred to produce F(sub 1a), F(sub1b) and F(sub1c) pups. The F(sub1b) adults were raised and bred to produce F(sub 2a), F(sub2b), and F(sub2c) pups. An Outbreeding Cohabitation was conducted by mating 10,000 ppm F1 males with naive females and 10,000 ppm F1 female with naive males. Parameters evaluated over the course of the study included body weights, feed consumption, clinical observations, vaginal cytology, reproductive performance neonatal anogenital distance (AGD), pup survival, sexual development, computer-assisted sperm analysis, gross pathology, organ weights, and selected histopathology. Body weights, feed consumption, clinical observations, incidental gross findings, and mortality were not adversely affected by any dose of DBP during the F0, F1, or F1 Outbreeding Cohabitations. During the F0 and F1 Cohabitations, there were several deaths with no apparent relationship to treatment. No mortality was observed among the F1 animals during the rearing or outbreeding periods. |
