¹Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Bursa Uludag University, TR-16059 Bursa - TÜRKİYE
²Department of Pathology, Faculty of Veterinary Medicine, Bursa Uludag University, TR-16059 Bursa - TÜRKİYE
³Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Bursa Uludag University, TR- 16059 Bursa - TÜRKİYE
⁴Department of Biotechnology and Bioengineering, Izmir Institute of Technology, TR-35430 İzmir - TÜRKİYE DOI : 10.9775/kvfd.2022.28403 The expressions of prostaglandin synthesis enzymes and estrogen, progesterone receptors in canine cystic endometrial hyperplasia (CEH) were reported in this manuscript. Uterine tissue samples were collected from bitches with CEH (n=5), CEH-P (Cystic endometrial hyperplasia-Pyometra) (n=5) and healthy-negative control group, CG (n=5). Immunohistochemistry was carried out for the estrogen (ER) and progesterone receptor (PR) detection. Shock-frozen samples were utilized in mRNA extraction and Real-Time PCR was performed. Gene expression of PTGS2/COX2, PTGES, PTGER4, PGFS, PTGFR and PGR were detected higher in the CEH group compared with CG. The PGFS and PTGFR (FP) mRNA expressions were significantly increased in CEH compared with other groups. Expression of progesterone receptor mRNA (PGR) was highest in CEH and statistically different from the CEH-P group (P<0.05). No PR immunostaining was observed. ER staining had been detected in endometrial glands, endometrial stoma and myometrium, however hyperplasic glands in propria mucosa had lower or no ER scores. Based on the results of this study, the high levels of prostaglandin enzymes and low ER scores in CEH could be a preliminary step for the next stages of severe differentiation of endometrium. Keywords : Canine, Cystic endometrial hyperplasia, Estrogen receptor, Prostaglandin