Pharmacokinetics and Effects of 17β-Estradiol and Progesterone Implants in Ovariectomized Rats

We describe a method to obtain sustained serum levels of estrogen or progesterone and the consequences of these sustained hormone levels on acute thermal nociception and the antinociceptive response to morphine. This rat model of hormone replacement may provide insights into the role of these hormones in pathological pain states.