目的 探讨体内过量全反式维甲酸（ATRA）对生长发育期SD大鼠的脑、心、肺、肝、肾和脾的影响。 方法 以48只3周雄性SD大鼠为实验对象，随机分为对照组和3个实验组，ATRA剂量分别为40、60、80 mg/(kg·d)，每组12只，进行连续10 d ATRA灌胃处理，记录SD大鼠每日体重,于灌胃第10天解剖称量各器官的重量以及计算脏器指数，然后对各器官进行HE染色。  结果 ATRA灌胃后，与对照组比较，40 mg/(kg·d) ATRA组肾指数升高，体重变化差异无统计学意义；60 mg/(kg·d) ATRA组体重降低，心、肾指数升高，脾脏重量降低；80 mg/(kg·d)ATRA组体重明显降低，脑、心、肾指数升高，脑、脾重量降低；HE染色显示，与对照组比较，ATRA处理组的肺泡壁增厚，肾小管上皮细胞有空泡样改变，脾脏红髓出现较多巨噬细胞，而大脑、肝脏、心肌无明显组织学变化。  结论 体内过量全反式维甲酸能够对生长发育期SD大鼠的肺、肾和脾有一定的损伤作用。

Objective To investigate the effects of overdose all-trans retinoic acid (ATRA) on brain, heart, lung, liver, kidney and spleen in developmental SD rats.   Methods Forty-eight male SD rats, 3-week-old, were divided into control group and three treatment groups at the doses of 40, 60, and 80 mg/(kg·d) of ATRA, respectively, 12 rats each group, the rats were administrated by gavage every day for 10 days. The rats body weight were weighed every day. After treatment, the rats were sacrificed and then rat heart, lung, liver, kidney, and spleen tissues were weighed, respectively. The organ index was calculated. The organs were then stained with HE staining.   Results After ATRA gavage, compared with the control group, the 40 mg/(kg·d) ATRA group had higher kidney index and body weight change was not statistically significant, the 60 mg/(kg·d) ATRA group had lower body weight, higher heart and kidney index, and lower spleen weight, and the 80 mg/(kg·d) ATRA group had significantly lower body weight, higher brain, heart and kidney index, and lower brain and spleen weight. HE staining showed that compared with the control group, SD rats in the 40, 60 and 80 mg/(kg·d) ATRA groups had thickened alveolar wall, vacuol-like changes in renal tubular epithelial cells, and more macrophages in the spleen, but no significant histological changes in the brain, liver and heart.   Conclusion Excessive all-trans retinoic acid in vivo could damage the lungs, kidneys and spleen in developmental SD rats.