The effect of exogenous estrogen and tamoxifen on murine experimental precancerous breast disease / 中华普通外科杂志

ABSTRACT

Objectiver　 To establish murine breast precancerous model and evaluate the effect of exogenous estrogen and tamoxifen.　 Method　 50 female Wistar rats were divided into contol group (n＝12), the other 38 received low dose carcinogen (DMBA) by gastrogavage, and then divided into DMBA group (common diet,n＝8); DMBA+DES group(DES added chow,n＝15); and DMBA+TAM group (TAM added chow,n＝15). 3 months later, the status of breast hyperplasia, AgNOR and DNA content were measured. 　Results　 All indexs in control group and DMBA+TAM group were normal.However,in DMBA group and DMBA+DES group,the breast hyperplasia rate was 75%, 93.3%, AgNOR was 3.71±0.76, 5.60±0.42, DNA was 88.59±7.17, 137.75±3.13 respectively.Compared with control group and DMBA+TAM group, the differences of indexes in DMBA and in DMBA+DES group were significant (P<0.01). 　Conclusion　 Low dosage DMBA administered by gastrogavage established breast precancerous model. Exogenous estrogen promotes the development of breast precancerous disease induced by DMBA, while TAM suppresses the canceration.