Novel methods in mammary gland evaluation [abstract]

Abstract

In response to the growing knowledge base on effects of environmental contaminants on mammary tissue, the National Toxicology Program (NTP) renovated their bioassay guidelines to adapt developmental chemical exposure and reproductive studies by including evaluation of mammary gland development. The normal development of mammary tissue in the Harlan Sprague Dawley (HSD) rat is not documented. Our goal is to create an encyclopedia of mammary gland development in both male and female HSD rat offspring, starting with gestational day 15 through postnatal day 70. In addition, prenatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin was used to demonstrate delayed mammary gland effects, and diethylstilbesterol was used to demonstrate precocious mammary gland effects in offspring.