己烯雌酚对催乳激素在小鼠淋巴结内表达的影响

Effects of diethylstilbestrol on the expression of prolactin in mice lymphoid nodes

目的探讨新生期雌性和雄性BALB/c小鼠接触己烯雌酚(DES)后其淋巴结内催乳激素(PRL)表达的变化,以及这种变化在两性之间是否存在差异。方法选取同窝及体重差异小于5%的新生BALB/c小鼠,随机分为DES组与对照组,雌、雄各选25对,在生后24 h内,DES组小鼠颈背部皮下注射DES,每隔24 h注射1次,共连续注射5次;对照组小鼠平行注射等量无菌豆油。分别在生后第7、21、35、49天和第63天将小鼠处死,每个时间点雌、雄各取5对小鼠,取其淋巴结进行常规石蜡包埋、切片及PRL的免疫组织化学检测。结果无论是对照组还是DES组,雌、雄小鼠从生后第7天至第63天,淋巴结内均可见到PRL阳性细胞,阳性细胞呈淋巴细胞形态结构特点,皮质和髓质均有分布。PRL阳性表达从生后第7天至35天逐渐增多,第35天后逐渐下降。同一时间点对照组和DES组相比较发现,无论是平均吸光度(AA)还是积分吸光度(IA)在DES组均高于对照组。在雌性小鼠,两组间AA在生后第35天有统计学差异,IA在生后第21天、35、49天和第63天均有统计学性差异,其中在第35天具有极显著差异(P<0.001)。在雄性小鼠,两组间AA在生后第35天有统计学差异,IA在生后第21天和第35天具有统计学差异。结论无论是雌性还是雄性BALB/c小鼠,其淋巴结内均存在PRL阳性表达细胞,表达水平在生后第35天达到最高。新生期接触DES可导致小鼠淋巴结内PRL阳性表达增加。雌性小鼠对DES的敏感性大于雄性小鼠,DES对雌性小鼠淋巴结PRL表达的影响至少可持续至成年期。

Objective To investigate the changes of prolactin （PRL） expression in lymphoid nodes of BALB/c mice treated with diethylstilbestrol （DES） in neonatal period and whether these changes differ from female mice to male ones. Methods Neonatal brood BALB/c mice whose weight discrepancies less than 5% were divided randomly into control group and DES group, and 25 pairs of female mice and 25 pairs of male mice were chosen in all. Within 24 hours after birth, mice in DES group were injected subcutaneously at cervix-backside with DES at intervals of 24 hours for 5 times, and mice in control group were injected with germ-free bean oil by the same way. Mice were killed on day 7, 21, 35, 49 and 63 after birth separately, and 5 pairs of female mice and 5 pairs of male mice were killed at each time point. The lymphoid nodes were taken out, imbedded with paraffin and sectioned serially in 5 Ixm. The expression of PRL in slices of lymphoid nodes was detected by immunohistochemistry technique. Results No matter in female or male mice, PRL positive cells were present in mice of both DES group and control group since day 7 until day 63 after birth. Prolactin positive cells were recognized as lymphocytes with typical morphological characteristics, and distributed in cortex and medulla. PRL expression in both groups increased in an age-dependent manner until day 35 after birth and then declined. At each the same time point, both the average absorbance （AA） and the integrate absorbance （IA） of PRL expression were higher in DES group than those in control group. In female mice, statistic differences were showed in AA on day 35 and in IA on day 21, 35 （P 〈 0. 001 ） , 49 and 63 after birth between the two groups. In male mice statistic differences were showed in AA on day 35 and in IA on day 21 and 35 between the two groups. Conclusion 1. In both female and male BALB/c mice PRL positive cells were present in their lymphoid nodes, and the level of PRL expression was the highest on day 35 after birth. Being reared with DES during neonatal period could lead an increased PRL expression in lymphoid nodes of BALB/c mice. The female BALB/c mice were much more sensitive to DES stimulation than male mice, and the effects of DES on female mice can continue to their adulthood at least.