The evaluation of the oxidative stress index of reproductive tissues and serum thiol/disulphide homeostasis during estrous cycle in bitches

Abstract

The aim of this study was firstly to determine the relationship between estrous cycle and oxidative stress in reproductive tissues in bitches. This research was performed in twenty-nine healthy bitches from different breeds and of varied ages (the range was 2-5 years) that were brought to the clinic for routine ovariohysterectomy. The stages of estrous cycle were detected using by vaginal cytology, blood progesterone level and histological findings. Ovarian, oviduct and uterine tissues were taken into Eppendorf tubes for oxidative stress index and stored at -80°C until analyses. Also, another part of these tissues were fixed in 10% formalin solution. There were no significant differences (P > 0.05) among total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) values in the reproductive tissues in concerning estrous cycle stages. However, there were remarkable correlations between oxidative stress parameters and reproductive tissues in different estrus stages in bitches. In conclusion, the physiological values of TAS and TOS concentration, and OSI in the ovarian, oviduct and uterine tissues during estrous cycle were firstly defined in this article. The serum thiol/disulphide homeostasis was also determined in the estrous cycle of bitches. We have found that there are remarkable variations of oxidative stress balance in the ovary, oviduct and uterus concurrently, during estrous cycle in the bitches. Besides, significant correlations between oxidative stress parameters and estrous cycle stages in the reproductive tissues were observed in the present study.