Effects And Mechanisms Of Restraint Stress During Peri-implantation On Pregnancy Outcome Of The Mouse

Restraint is an experimental procedure developed for biomedical studies of stress.'Psychogenic'or'psychosomatic'refers to the term that the stress response initiated in the brain responds to the psychological distress caused by restriction in movements without physical injury. The hypothalamic–pituitary–adrenal (HPA) axis, when activated by stress, exerts an inhibitory effect on the female reproductive system.In our study, a restraint system was established to allow mice intake of food and water freely in case of additional effects of hunger and thirsty, and at the same time to restrain their movement to ensure that mice could neither move back and forth nor turn around in the micro-cage. The peri-implantation mice are subject to a continuous stress lasting for 24h to simulate the psychological stress.The restraint stress starting at 7:30 am on d4 of pregnancy led to drastic harm on gestation, involving high rate of abortion and decreased litter size. The research on its mechanism illustrates that the restraint stress made impact on the altered concentration of progesterone in serum, decreasing the concentration of progesterone .the delayed process of implantation, the declined the number of implantation site, low rate of incubated blastocysts, and the blockage of attachmentreaction. Further study demonstrates that the restraint stress decents the expression of the key implantation regulator---HB-EGF, probably resulting in the delayed implantation, and obstructs the development of embryos and fetus, inducing abortion and infertility.