Effects of olive, corn, sesame or peanut oil on the body weights and reproductive organ weights of immature male and female rats.

Olive, corn, sesame or peanut oil which have been used as vehicles in the immature rat uterotrophic assay or Hershberger assay, for detection of endocrine disrupting effects of environmental chemicals, was administered to ten immature female rats by subcutaneous injection from postnatal day (PND) 21 for 3 or 7 days, and each oil was also administered to ten male rats from PND 21 for 7 and 10 days. The body weights, and the weights of sex and sex accessory organs in female and male rats were measured. There were no significant differences in body weights of female rats between each oil group and the control group, while the body weight of male rats in the group given peanut or olive oil was significantly increased from 8 or 9 days after administration. There were no changes in the sex and sex accessory organ weights of female or male rats related to the endocrine disrupters. The results of the body weights and organ weights demonstrate that each oil is a suitable vehicle for the immature rat uterotrophic assay. However, each oil is suggested to be unsuitable for the Hershberger assay, because the analysis of changes of sex accessory organ weights in this assay might be confused by the increased body weights.