Periimplantation uterus studies were conducted with virgin female Balb/c mice. Ligated uterus studies were done with virgin female Balb/c mice with one uterine horn ligated at the oviductal-uterine horn junction at least 2 wk before mating. In both studies, female mice were mated with male mice of the same strain from 1700 to 0900 h. Mating was confirmed by the presence of a vaginal plug (Day 1 of gestation). Mice were killed on Days 2 through 7 of pregnancy. Tissue was rapidly removed and fixed in 4% paraformaldehyde. Before embryo implantation, pregnancy was confirmed by flushing the oviducts or uterus and visualizing the embryos. After embryo implantation, pregnancy was confirmed by the presence of visible implantation sites in the uteri of mice after five days of gestation. buy prednisone
In the deciduomata-induced uterus studies, virgin female Balb/c mice were mated with vasectomized males. Mating was confirmed by the presence of a vaginal plug (Day 1 of pseudopregnancy). On Day 4 of pseudopregnancy, mineral oil was injected into one uterine horn of female mice to stimulate a decidual reaction. The contralateral, uninjected uterine horn served as a control. Mice were killed at 24, 48, and 72 h after oil injection. Tissue was rapidly removed and fixed in 4% paraformaldehyde. Decidualization was confirmed by histological examination of uterine sections stained for alkaline phosphatase activity.