Abstract |
Alterations in the developmental processes of embryos resulting from exposure to chemicals are not limited to morphological abnormalities that can be observed in the near term fetus. In the research on the developmental toxicology of pesticides the authors have noted morphological defects (cataracts, ablation of Harderian gland development, malformation of the otoliths) in postnatal offspring exposed prenatally that could not be detected in fetal examinations because of the immature nature of these structures at that stage of development. In addition, other effects on physiological functions have been detected (locomotor hyperactivity, and decreased renal concentrating ability) that have no obvious morphological basis. Thus, a postnatal component of a standard teratology bioassay can yield critical new information in the overall assessment of developmental toxicity. |