Differences in Prepuberal Neonatally Estrogenized or Androgenized Male Rats

The main objective of this work was to analyze the different effects produced in prepuberal male rats by neonatal androgenization or estrogenization. For this purpose male Wistar rats were injected on day one of life with 500 micrograms of estradiol benzoate (estrogenized animals), 500 micrograms of testosterone propionate (androgenized animals) or olive oil (control animals) and decapitated on day 15. At the moment of decapitation estrogenized animals showed decreases in body, testes, prostate and adrenal weights, increases in pituitary, seminal vesicles and epididymis weights, an increase in prolactin plasma levels and a decrease in those of androgens. Androgenized animals showed only decreased testes and epididymis weights and androgen plasma levels. These results evidence the presence of important qualitative differences in prepuberal neonatally estrogenized or androgenized rats, especially in the accessory sex organs.