Lei Zhiming, Ruan Ming, Qiu Feichan, Wei Xuetao, Li Xueting, Jia Fenglan, Shang Lanqin, Zhang Baoxu
Department of Toxicology, School of Public Health, Peking University, Beijing 100083, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2002 Nov;36(6):398-401.
To study the immunotoxicity induced by 9,10-dimethyl-1,2-benzathrancene (DMBA) in metallothionein gene-knocked-out mice [MT(-/-)] as compared with that in wild-type mice [(MT(+/+)].
Female mice were treated with 25 mg/kg and 50 mg/kg of DMBA i.p., respectively and immunized with sheep red blood cells (SRBC) i.v. on the following day and rechallenged by injection of SRBC via footpad s.c. on the fourth day post-immunization. Humoral and cell-mediated immune function was assessed by the number of spleen IgM antibody plaque formation cells (PFC) to SRBC and cell-mediated delayed-type hypersensitivity (DTH) measured by footpad swelling thickness.
After treatment with 25 mg/kg DMBA, a decrease in weight of their spleen and thymus and PFC/spleen were observed in MT(-/-) mice, while only decrease in thymus weight of MT(+/+) mice. The humoral function was suppressed by 72% in MT(-/-) mice. No obvious change in cell-mediated immune function was observed both in MT(-/-) and MT(+/+) mice. Both humoral and cell-mediated immune function were suppressed more severe (91%) in MT(-/-) mice treated with 50 mg/kg DMBA than those treated with 25 mg/kg DMBA (72%). DTH was not altered by DMBA in MT(+/+) mice. The weight of their spleen and thymus decreased and humoral immune function suppressed in MT(+/+) mice, but these changes were significantly less severe. No obvious suppression of cell-mediated immune function was observed in MT(+/+) mice.
Their humoral and cell-mediated immune function was more susceptible to being suppressed by DMBA in MT(-/-) mice, indicating that MT could protect their immune function from damage caused by DMBA.
研究9,10 - 二甲基 - 1,2 - 苯并蒽（DMBA）对金属硫蛋白基因敲除小鼠[MT(-/-)]诱导的免疫毒性，并与野生型小鼠[MT(+/+)]进行比较。
雌性小鼠分别腹腔注射25 mg/kg和50 mg/kg的DMBA，次日静脉注射绵羊红细胞（SRBC）进行免疫，免疫后第4天通过足垫皮下注射SRBC进行再次攻击。通过对SRBC的脾脏IgM抗体斑块形成细胞（PFC）数量评估体液免疫和细胞介导免疫功能，通过足垫肿胀厚度测量细胞介导的迟发型超敏反应（DTH）。
用25 mg/kg DMBA处理后，MT(-/-)小鼠脾脏和胸腺重量以及PFC/脾脏数量减少，而MT(+/+)小鼠仅胸腺重量减少。MT(-/-)小鼠的体液功能受到72%的抑制。MT(-/-)和MT(+/+)小鼠的细胞介导免疫功能均未观察到明显变化。用50 mg/kg DMBA处理的MT(-/-)小鼠的体液和细胞介导免疫功能比用25 mg/kg DMBA处理的小鼠（72%）受到更严重的抑制（91%）。DMBA对MT(+/+)小鼠的DTH无影响。MT(+/+)小鼠的脾脏和胸腺重量下降，体液免疫功能受到抑制，但这些变化明显较轻。MT(+/+)小鼠未观察到明显的细胞介导免疫功能抑制。
MT(-/-)小鼠的体液和细胞介导免疫功能更容易受到DMBA的抑制，表明MT可以保护其免疫功能免受DMBA造成的损害。
