title: [Effects of levonorgestrel intrauterine system on endometrial tissue after endometrial polyps resection by hysteroscopy].
abstract: OBJECTIVE
  To explore the changes of endometrial tissues after the insertion of levonorgestrel intrauterine system (LNG-IUS).
  
  
  METHODS
  The endometrial tissues were harvested from 21 cases after endometrial polyps resection by hysteroscopy. And the patients received a 1-year follow-up. The immunohistochemical stains for estrogen receptor (ER), progesterone receptor (PR), Ki-67, bcl-2 and bax were used for semi-quantitative analyses. The changes of endometrial thickness were monitored and uterine weight was observed with a 3-year follow-up.
  
  
  RESULTS
  The endometrial thickness and uterine weight declined continuously after the insertion of LNG-IUS. The endometrial thickness decreased from the preoperative level of (9.8 ± 1.2) mm to (3.5 ± 1.0) mm while the uterine weight dropped from the preoperative level of (98.8 ± 8.6) g to (66.6 ± 9.8) g. The expressions of ER, PR and Ki-67 were significantly lower than those of the para-polyps endometrial tissue (P < 0.05). The expressions of bcl-2 and bax were significantly higher than those of the para-polyps endometrial tissue (P < 0.05).
  
  
  CONCLUSIONS
  LNG-IUS may prevent the recurrence of uterine endometrial polyps through its inhibited expressions of ER, PR and Ki-67 and induced endometrial apoptosis.
authors.affiliation: Ruian People's Hospital, Ruian 325200, China. Email: caihuilan123@163.com.
authors.forename: Hui-lan
authors.initials: HL
authors.lastname: Cai
authors.forename: Xiang-cui
authors.initials: XC
authors.lastname: Ding
authors.forename: Rong-rong
authors.initials: RR
authors.lastname: Qian
authors.forename: Ru-fen
authors.initials: RF
authors.lastname: Yu
authors.forename: Li-min
authors.initials: LM
authors.lastname: Sun
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
mesh_terms: D000328:Adult; D004717:Endometrium / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007436:Intrauterine Devices, Medicated; D016912:Levonorgestrel / Q000008:administration & dosage / Q000494:pharmacology*; D011127:Polyps / Q000473:pathology* / Q000517:prevention & control / Q000601:surgery; D011184:Postoperative Period; D014594:Uterine Neoplasms / Q000473:pathology* / Q000517:prevention & control / Q000601:surgery
chemical_list: D016912:Levonorgestrel