Immunohistochemical Detection of Estrogen and Progesterone Receptors in the Uterine and Oviductal Tissues of Culling Gilts with Ovarian Cysts

Abstract

The most important removal cause of replacement gilts that occurred in the swine herds is the reproductive failure. The widespread causes of reproductive problem are induced by various factors and ovarian cysts were frequently found among these. The objective of this study was to scrutinize the impact of ovarian cysts on the expression of female steroid receptors in the uterine horns and oviducts of culling gilts. The genital organs were collected from culled replacement gilts which were categorized into three groups: gilts with single large cyst, multiple large cysts and normal ovary at follicular phase (control). The historical data were gathered for analyzing the relationship between culling reasons and ovarian cystic types. Blood samples were collected for examining the progesterone level. The immunohistochemical study was performed to elucidate the localization of estrogen receptor alpha (ER) and progesterone receptor (PR). Anestrus was the major culling reasons (50%) that found in the replacement gilts with multiple large ovarian cysts and progesterone level (45.8±21.2 nmol/l) was elevated in this group. The intensity and proportion of ER and PR nuclear positive staining detected in uterine horns and oviducts were lower in the group of multiple large ovarian cysts compared with the other groups. The investigations indicated that the malfunctions in ovarian hormonal synthesis, particularly the abnormal level of progesterone, influence on the expression of female steroid receptors in the uterine horns and oviducts. This occurrence may describe that the multiple large ovarian cysts were the important reason to reduce the functional efficiency of reproductive tracts and may be the main reason of anestrus found in the replacement gilts.