Distribution of estrogen receptor α and progesterone receptor B in the bovine oviduct during the follicular and luteal phases of the sexual cycle: an immunohistochemical and semi-quantitative study

The aim of our study was to determine the distribution of estrogen receptor α (ERα) and progesterone receptor B (PR-B) in the bovine oviduct during the follicular and luteal phases. Bovine oviducts from 23 animals were obtained from a local slaughterhouse. Blood samples from these animals also were taken before death to measure estrogen and progesterone levels. The serum levels of estradiol-17β and progesterone changed during the estrous cycle. Tissue distribution of ERα and PR-B was examined using immunohistochemical techniques and the results showed that ERα and PR-B were stained in nuclei of cells and could be detected in all compartments along the entire oviduct during both the follicular and luteal phases. During the follicular phase, no significant differences were found between ERα and PR-B distribution (p < 0.05), while significant differences were found between ERα and PR-B during the luteal phase (p < 0.05). We results indicated that the frequency and intensity of ERα and PR-β immunoreactivity in the oviduct of bovines varied according to the oviductal cell types and the phases of the sexual cycle.