Treatment Of Experimentally-induced Uterine Adenomyosis With Letrozole

OBJECTIVEAdenomyosis is the benign invasion of endometrial glands and stroma deep and into the myometrium ,it is a common disease in department of gynecology. At present, the pathogenesis of adenomyosis is not completely clear,and there are not satisfactory method. It is important to use animal models to study this disease.Our study is to investigate the effectiveness of letrozole on experimentally induced uterine adenomyosis in BALB/c mice.METHODSA single pituitary was transplanted in the lumen of the right uterins of 30 virgin female BALB/c mice at the age of 7 weeks respectively,as pituitary grafting quickly induced the development of uterine adenomyosis.Mice were randomly divided into 3 groups,10 of each,5 months after pituitary grafting.The treatment groups received 4 weeks of letrozole treatment,0.38mg/kg and 0.75mg/kg respectively. The mouse of NS group were received 4 weeks of saline.There were 10 mouse which were not transplanted as a control group. All mice were then killed and the uteri and ovaries were weighed. levels of Serum E2,FSH,LH were determined.The right uteri were examined under a 20-fold microscope.RESULTS(1) Uteri in treatment groups were thinner and less congestive compared with those of the NS group after 4 weeks.Uteri in untransplanted group were light red,smooth surface,no adenomyosis nodules.(2) There was no statistical difference in the body weight and the ovarian wet weight in each groups.( the body weight F=3.969 P=0.015;the ovarian wet weight F=0.496 P=0.688). there were statistical difference in the uterine wet weight, uterine wet weight/body weight ratio in each groups(.the uterine wet weight F=876.105 P< 0.05;uterine wet weight/body weight ratio F=283.443 P<0.05).(3) There were statistical difference in scores of HE stained uterine and incidence in each groups(disease incidence X2=20.608 P<0.05; scores of HE stained uterine F=64.182 P<0.05). disease incidence in NS group and treatment groups were higher than untransplanted group,but there was no statistical difference in NS group and treatment groups.(4) There was no statistical difference in levels of Serum E2,FSH,LH in each groups.( Serum E2:F=0.101 P=0.959; Serum FSH:F=1.956 P=0.138;Serum LH:F=1.297 P=0.290)CONCLUSION(1) The method of using BALB/c mice to make the adenomyosis models is successful.This model had a high incidence and its pathologic changes were close to those of adenomyosis(AM),so it might be an ideal model for the researching AM.(2)Four weeks of Letrozole treatment suppressed its adenomyosis in a mouse model although it could not cure the disease and the levels of Serum E2,FSH,LH were not changed.