Influence of Multiple Ovarian Cysts on the Immunohistochemical Localization of Progesterone Receptor in the Gilt Endometrium

Introduction In the swine farms, the reproductive disorders composed of repeat breeding, vaginal discharge, anestrus, not getting pregnant and abortion are the main problem resulting in culling lots of gilts (1). It is known that reproductive function of gilts is complicated to clinically explore under field surroundings, thus the reproductive organs from the slaughterhouses are the possible source for investigating the various reproductive problems (2). The pig uterus is regulated by the intricate actions of ovarian steroid hormones and the appropriate hormonal levels can build a suitable milieu within endometrium (3). Undeniably, the ovarian abnormalities must disrupt the uterine function leading to infertility (4). In Thailand, most ovarian disturbances found in gilts culled due to reproductive failure are the ovarian cysts (60%) and the multiple cysts were significantly detected among these gilts (5). Since the ovarian cysts are counted as the hormonal disease and the female steroid hormones accomplish their functions by binding through exact receptors (6). It is expected that the expression of these receptors in the target tissues could reveal the efficiency of female hormonal function. Therefore, the aim of this study was to determine the impact of the multiple ovarian cysts on the localization of progesterone receptor in the culling gilt endometrium.