The Infulence Of Apoptosis Exerted By CO₂ Gas On The Ectopic Endometrial Cell Of SCID Mouse And Its Significance

Background:Endometriosisis is defined as the presence of endometrial glands and stroma outside the uterus and myometrium, is one of the most frequent benign gynecological diseases that affects 10% of women of reproductive age with pelvic pain, infertility and dysmenorrhea.The pathogenesis of this disease still remains unknown science Sampson first described this disease in 1921. Accumulated evidence suggests that apoptosis helps to maintain cellular homeostasis during the menstrual cycle by eliminating senescent cells from the functional layer of the uterine endometrium during the late secretory and menstrual phase of the cycle. Accumulating evidences also suggest that decreased spontaneous apoptosis in eutpic and ectopic endomtrial cells may promote the occurrence and development of EMs.Comapared with laparotomy,laparoscopy has resulted in dramatic decrease in hospital stay, an increase in patient's comfort ,and a more rapid return to normal daily activities.Laparoscopic surgery becomes the first choice for endometriosis diagnosis and treatment.But the problem of recurrent endometriosis after laparoscopic surgery always troubled,also attract more and more researchers, attention in recent years. So far little research has been emphasized on the influence of CO2 pneumoperitoneum on recurrent endometriosis after laparoscopic surgery and its pathophysiological changes.Objectives:In this paper, we reviewed the role of cell apoptosis in endometriosis occurrence and development ,and the role of CO2 pneumoperitoneum in tumor metastasis, then establish endomtriosis model and CO2 pneumoperitoneum in SCID mice.Our aim is to explore whether CO2 inhibit the apoptosis in ectopic endometrial cells and influence the recurrence and metastasis of endometriosis after laparoscopic surgery.Materials and Methods:Proliferative phase endometrial tissue was obtained from women during hysterectomy who had uterine myomas.Then establish endomtriosis model by suturing the endometrium into the mice bi-abdominal walls and CO2 pneumoperitoneum in SCID mice (n=60), CO2 gas pressure maintained at 5mmHg for 60min or120min, we then detect apoptosis index of ecotpic endometrial cells in SCID mice using the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay.All values were expressed as mean±standard deviation (X±S).Results were annlyzed using the Student's t test (T test).When p value less than 0.05 it was considered statistically significant.Use the SPSS15.0 software to analysis.Results:1. Successful implantation of EMs was observed in 37 of 60 surviving mice following suturing, with a success rate of 61.67%.Endometrial cysts within the range 0.2cm～1.0cm in diameter, the appearance of the cyst were transparent or fresh bright white, fill with fluid, cyst wall surface covered with blood vessels, mild abdominal adhesions. Haematoxylin-eosin staining of implanting lesions demonstrated the presence of endometrial glandular tissue in a background of stromal cells.2.Successful rate of SCID CO2 pnumoperitoneum was 86.49%(32/37)3.The results of apoptosis cells detected(1)We could see apoptosis cells (glandular epithelial cells and stromal cells) in experimental groups and control groups ,under the fluorescence microscope chromatin condensation, marginalization, nuclear membrane lysis, chromatin is divided into blocks, and the typical apoptotic bodys could been seen.Hematoxylin counterstained, under the light microscope, apoptotic epithelial and stromal cells were stained dark brown.(2)Apoptosis index of endometrial glandular celles and stromal cells in experimental groups and control groups decreased with time elapsed,in which F group (120min,2 months) versus B (gasless pneumoperitoneum,2 months) has significant difference (P<0.05),F group (120min,2 months) versus the D group (60min,2 months) has significant difference (P<0.05), F group (120min,2 months) versus the E group (120min,1 month) has statistically significant difference (P<0.05), other groups have no significant difference (P>0.05).(3)Stromal cells has a lower apoptosis index compared with glandular cells in the same groups ,but has no significant difference (P> 0.05).Apoptosis index of endometrial.Stromal cells in experimental groups has a decreased trend compared with the gasless pneumoperitoneum groups ,the difference was not statistically significant(P >0.05).And the longer time inflation the more significantly decreased of apoptosis index ,but the difference was statistically significant (P> 0.05).Conclusions:1. Endomtriosis model can be established by suturing the endometrium into the mice bi-abdominal walls, the model has a higher successful rate with a longer effective period and a accurate position and easy to observe, repeatability .It is an ideal animal model for endometriosis study.2.Establish pneumoperitoneum CO2 pneumoperitoneum in SCID mice useing self-made pneumoperitoneum device, has a higher successful rate, the model can simulate the state of CO2 pneumoperitoneum in laparoscopic surgery and can be widely used in experiment.3.CO2 gas has a negative regulation on apoptosis of SCID ectopic edometrial cells ,suggesting that CO2 gas used in laparoscopic surgery may has some role in promoting the recurrence of endometriosis after laparoscopic surgery.