The Effect Of Chronic Restraint Stress On Murine Ovarian Follicular Development And Its Mechanism

Objective:The current social competition is becoming increasingly fierce and the pace of life is accelerating,chronic stress has become a major problem that endangers people’s physical and mental health.Studies have found that stress also negatively affects the animal’s reproductive system and reproductive capacity,causing reproductive endocrine disorders and decline in reproductive reserves.However,its mechanism is not fully understood.Studies have shown that P2X7 R is involved in a variety of chronic stress induced pathological changes.P2X7 R is a non-selective gated cation channel activated by high concentrations of ATP,which is widely distributed in different types of cells.Whether P2X7 R is involved in the effect of chronic stress on ovarian function has not been studied.In this study we will explore the effect of chronic stress on the development of ovarian follicles and observe whether P2X7 R is involved in the process.Methods:To establish a chronic restraint stress model,80 Kunming female mice with normal menstrual cycles were randomly divided into 4 groups,the control group,the stress group,the BBG(P2X7R inhibitor)group,and the BBG plus stress group(n=20).The mice in the stress group and the BBG plus stress group were put into a 50 ml centrifuge tube per day for 4 hours.The BBG group and the BBG plus stress group were injected with BBG daily through the abdominal cavity 50mg/kg,while the control group was injected with the same amount of normal saline via the abdominal cavity for 8 weeks.Each mouse was smeared with genital secretions at 7 am every day,monitoring the changes in the estrous cycle of mice through genital smears.Chemiluminescence was used to detect serum estradiol and progesterone levels;HE staining of ovarian tissue was used to assess the follicle development;Real-time quantitative PCR and Western blotting were used to detect the expression of P2X7 R in the ovary;BBG(P2X7R inhibitor)was injected intraperitoneally to observe whether it could relieve the effects of chronic stress on the ovaries.Results:We found that the weight in chronic restraint stress mice was lighter than control mice.Vaginal smears and Wright staining showed the estrous cycle in chronic restraint stress mice was prolonged.There was no change in serum estradiol level in two groups,while progesterone level in chronic restraint stress mice was significantly lower than control mice.HE staining showed that the number of corpus luteum was significantly reduced in chronic restraint stress mice,indicating that the ovulation was decreased.Real-time quantitative PCR and and Western blotting showed that the expression of P2X7 R in the ovary of the stress group was significantly increased.After treatment with BBG,one inhibitor of P2X7 R,the decrease of ovulation and progesterone secretion induced by chronic stress were partially alleviated.Conclusion:1.The chronic restraint stress mice gained weight slowly and their estrous cycle was disordered.2.The number of corpus luteum in ovaries and progesterone secretion were significantly reduced in chronic restraint stress mice.3.The expression of P2X7 R was increased in the ovaries of chronic restraint stress mice.BBG can partially restore the effects of chronic stress on ovulation and progesterone secretion.