hCG对实验性大鼠乳腺癌化学预防作用的研究

Chemopreventive effect of hCG on rat mammary carcinogenesis

目的:探讨人绒毛膜促性腺激素(hCG)对甲基亚硝脲(MNU)诱导的实验性大鼠乳腺癌的化学预防作用。方法:选取50 d龄雌性未经产SD大鼠60只,随机分为hCG早干预组、hCG晚干预组、他莫昔芬(TAM)组、暴露组和空白对照组。在鼠龄276 d时处死所有大鼠,取乳腺组织进行病理学检查。结果:hCG早干预组、hCG晚干预组、TAM组、暴露组和空白对照组大鼠的乳腺癌发生率分别为8.3%(1/12)、16.7%(2/12)、9.1%(1/11)、60.0%(6/10)和0(0/12)。hCG早干预组和hCG晚干预组大鼠乳腺中分化较成熟的小叶(Lob)、泡状芽苞(AB)比例高于暴露组,而未充分分化的终末导管(TD)、终末芽苞(TEB)比例低于暴露组。非成癌组大鼠乳腺中分化较成熟的Lob和AB比例高于成癌组,而未充分分化的TD和TEB比例低于成癌组。结论:在对未经产SD大鼠予致癌剂MNU之前,hCG可以显著降低大鼠乳腺癌的发生率;hCG预防乳腺癌发生的机制可能是促进了乳腺结构的分化成熟。

OBJECTIVE： To explore the chemopreventive effect and mechanism of human ehorionic gonadochopin（hCG） on mammary eareino genesis induced by methyl-nitroso-urea（MNU）. METHODS; Sixty female, virgin,Sprague- Dawley and 50 d rats were divided into five groups ran domly. Early hCG intervention group, Later hCG intervention group, TAM group, Exposure group,Control group. All the 60 rats were killed when 276 days old, the mammary tissues were obtained for pathological analysis,the incidences of adenocareinomas and the proportions of various kinds of mammary structures were evaluated. RESULTS.. The incidence of mammary adenocarcinomas in early hCG intervention group, later hCG intervention group, TAM group, exposure group, control group was 8. 3 （1/12）, 16.7%（2/12）, 9.1%（1/11）, 60.0%（6/10） and 0, respectively. The proportions of the more differentiated structure Lobule （Lob） and Alveolar buds （AB） in early hCG intervention group and later hCG intervention group were more than exposure group, the proportions of the less differentiated structure Terminal duct （TD） and Terminal end buds（TEB） were less than exposure group. The proportions of Lob and AB in adenocarcinoma-absent were more than adenocarcinoma-present group. The proportions of TD and TEB were less than adenocarcinoma-present group. CONCLUSIONS.. The administration of hCG can decrease the incidence of mammary adenoearcinomas induced by MNU on SD rats. The ehemopre ventive effect of hCG on the rat mammary carcinogenesis might be derived from the differentiation of mammary structures.