来曲唑对SD大鼠子宫内膜异位症模型的影响及其机制OA

Objective To investigate the effect of letrozole on a rat model of endometriosis(EMs)and its potential molecular biological mechanism.Methods Thirty 8-week-old female SD rats were used to establish endometriosis models via autologous uterine trans-plantation,and then randomly divided into three groups:model group,letrozole group,and ovariectomy group,with 10 rats in each group.After four weeks of intervention,serum levels of estradiol(E2),testosterone,follicle-stimulating hormone(FSH),and luteinizing hormone(LH)were measured by ELISA.The volume of endometriotic lesions was measured using Vernier calipers,and the shrinkage rate was calculated.Histological changes of endometriotic lesions were observed by HE staining.Protein and mRNA expressions of β-catenin,c-Myc,Cyclin D1,Bcl-2,and Bax in endometriotic lesions were detected by immunohistochemistry and RT-qPCR.Results Compared with model group,the lesion volumes in letrozole group and ovariectomy group significantly reduced(P<0.05),while there was no statistically significant difference between letrozole group and ovariectomy group(P>0.05).Glandular epithelial atrophy was observed,and stromal fibrosis was aggravated in letrozole group and ovariectomy group.Compared with model group,serum E2 level significantly decreased in letrozole group and ovariectomy group(P<0.05),and E2 level in ovariectomy group was lower than that in letrozole group(P<0.05).Compared with model group,testosterone level increased in letrozole group but decreased in ovariectomy group(P<0.05);FSH and LH levels were significantly elevated in both tletrozole group and ovariectomy group,and they were signifi-cantly higher in ovariectomy group than in letrozole group(P<0.05).Compared with model group,the subcellular localization of β-catenin was altered in both letrozole group and ovariectomy group,meanwhile,the protein and mRNA expressions of c-Myc,Cyclin D1,and Bcl-2 were significantly down-regulated while the expression of Bax was significantly up-regulated in letrozole group and ova-riectomy group(all P<0.05),and all indicators were numerically lower in letrozole group than in ovariectomy group,but there was no statistical difference(P>0.05).Conclusion Letrozole can significantly reduce E₂ level and inhibit endometriotic lesion growth in a rat model of endometriosis,with efficacy comparable to ovariectomy,which may be related to the inhibition of Wnt/β-catenin signaling pathway.