To Establish The Rat Model Of Pof And Investigate Its Mechanism Using The Method Of Physical And Mental Stress

Objective This investigation eatablish the rat model of POF by means of exerting a longtime physical and mental stress(PMS) to the mature rats and observe the change of NE in brain and serum, the corticosteron, FSH, E2, INHB in serum and the expression of bax, VEGF protein and GDF-9B mRNA in ovarian tissue of POF rats.Method 55 SD rats were devided into two groups randomly, normal group and model group. The normal group was give routine feeding without treatment. The model group was given PMS every day for 28 days continuously, those methods of PMS came from the national usual ways and some new ways. Each method would be selected randomly. When dealing with a part of model rats, the other part of rats was put at the side, in order to stress the mental of those rats. During this period, we observed the estrous cycle and behavior of both groups. On the 29th day, we put the two groups of rats to death, then collected the ovarians, serum and brains. The ovarian of rats were examined by HE-staining, and the morphological chang was assessed with light microscope. S-P immunohistochemical method were used to detecte the expression of bax and VEGF. Radioimmunoassay method were used to detect serum FSH and E2 contention. We used ELISA method to detecte the NE, CS, INHB and Realtime-PCR to observe the level of GDF-9B mRNA.Results1.Compare with the normal group, the average weight of model group rats was decreased(P<0.01) and bite frequency, the number of washing face were also decreased. their fur was dry and lack luster, the move is not flexible, their estrous cycle were also disorder.2.Normal rats ovarian had plenty of normal follicles and had rich luteals which volume were big and uniform; ovarian of model rats lack of normal follicle(P<0.05) and luteal(P<0.01), the volume of luteal was also smore and not uniform. The model ovarian had larger number of atresia follicle than the normal group(P<0.01).3.Compare to the normal group, the level of FSH, CS and NE in serum of model group were increased(P<0.01) and the level of E2 was decreased(P<0.05), INHB level had also decreased(P<0.01) in serum. Compare with the normal group, the NE contention in the brian of model group had decline trend both in pituitary and hypothalamus, but only the level of NE in pituitary was notablely decreased (P<0.05).4.Compare to the normal group, the expression of bax protein of model group was increased(P<0.01), while the VEGF protein contention was decreased(P<0.05). Eventhough nomal group had richer contention of GDF-9B mRNA than model group, the difference had no statistics significance.Conclusion1.PMS is an impotant factor which can induce part of rats happen POF.2.PMS would break neurotransmitter secretion way and cause the H-P-A,H-P-G axises and spirit-nerve-endocrine disorder, at last affect the ovarian normal function.3.PMS would decline ovarian artery VEGF contention, increased the bax protein expression, affected the GDF-9BmRNA, and then aggravated the oocytes atresia and ovarian fail.