Hirata-Koizumi Mutsuko, Matsuyama Takashi, Imai Toshio, Hirose Akihiko, Kamata Eiichi, Ema Makoto
Division of Risk Assessment, Biological Safety Research Center, National Institute of Health Sciences, Tokyo, Japan.
Drug Chem Toxicol. 2008;31(2):275-87. doi: 10.1080/01480540701873368.
In our previous toxicity studies using young rats, we showed that an ultraviolet absorber, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole (HDBB), principally affected the liver, and male rats had nearly 25 times higher susceptibility to the toxic effects than females. In the present study, the toxicity of HDBB was investigated in preweaning rats. HDBB was administered by gavage to male and female CD(SD) rats from postnatal days 4 to 21 at a dose of 0, 0.1, 0.5, 2.5, or 12.5 mg/kg/day. No substance-related deaths, clinical signs of toxicity, or body-weight changes were observed. Increased levels of albumin, AST and ALP in both sexes, BUN in males, and LDH in females were found at 12.5 mg/kg. Liver weights increased at 2.5 mg/kg and above in both sexes. Histopathologically, hepatocellular findings, such as nucleolar enlargement, anisokaryosis, increased mitosis, and/or hypertrophy, were observed at 2.5 mg/kg and above in both sexes. These results indicate no gender-related differences in the susceptibility to the toxic effects of HDBB in preweaning rats.
