镉接触对妊娠期及哺乳期大鼠及仔代生长发育的影响

Influence of cadmium exposure during gestation and lactation on the growth and development of the second generation in rats

目的 观察妊娠期及哺乳期镉接触对大鼠性别分化、生长发育和青春期启动的影响 ,以及其可能的内分泌干扰机制。方法 SD雌性大鼠从妊娠第 1天开始至仔鼠断奶 ,自由饮用含 0、5、2 0和 40mg L氯化镉的水。结果 各剂量组仔鼠的生长发育、青春期启动均受到明显影响 :出生后 (PND) 2 1d体重明显低于对照组 ;阴道开放、包皮分离比对照组延迟 2～ 3d。但是 ,各剂量组对妊娠时间、着床数、每胎活产数、性别比例、肛殖距离没有明显的影响。结论 在该实验条件下 ,并未显示镉具有雌激素样活性。镉可能通过多种机制 ,如甾类生成、甲状腺、垂体性腺轴等 ,干扰内分泌系统 ,从而影响大鼠的生长发育、青春期启动。

Objective This study aimed to assess the effects of cadmium exposure during gestation and lactation period on sex differentiation, growth and development, and initiation of puberty of the pup rats, and to explore its possible mechanism related to endocrine disruptor. Methods Pregnant SD rats were freely administered with drinking water contained 0,5,20,40 mg/L of cadmium chloride. Results It was observed that all doses of cadmium chloride have significant effects on the growth and development, initiation of puberty of the pup rats; the body weight of pup rats at postnatal day 21 decreased significantly; Vaginal opening and preputial separation were postponed up to 2～3 days compared to control. However, there were no significant effects on gestation and sex differentiation with different doses of cadmium chloride. Conclusion It was suggested that cadmium have no affirmed estrogenic activity under our experimental condition, it might affect the development and initiation of pubertal of pup rats through various mechanisms related to endocrine disrupting such as steroidogenesis, thyroid, and pituitary gonad axis.