2-乙酰基-4-四羟基-丁基咪唑对成年雌性大鼠的免疫毒性研究

doi:10.3969/j.issn.1004-616x.2023.02.001

摘要/Abstract

摘要： 目的：探究Ⅲ类焦糖色制作过程中的主要副产物2-乙酰基-4-四羟基-丁基咪唑(THI)对雌性大鼠免疫系统的影响。方法：选取50只健康成年的SPF级雌性SD大鼠，随机分为5组，每组10只，进行THI经口灌胃染毒，剂量分别为0、0.1、0.5、2.5和5mg/kg，连续染毒30 d。记录大鼠体质量并测定胸腺和脾脏的脏器系数，取大鼠胸腺进行组织病理学观察，用全自动血细胞分析仪检测外周血中白细胞及各分类细胞的数量，通过淋巴细胞转化试验测定脾脏T淋巴细胞的增殖能力，用乳酸脱氢酶法测定脾脏NK细胞的活性，利用流式细胞术分析外周血、胸腺和脾脏中主要免疫细胞的比例变化。结果：THI染毒可使大鼠胸腺皮质/髓质面积比下降。与对照组相比，2.5和5 mg/kg的THI染毒能降低大鼠脾脏T淋巴细胞的增殖能力(P<0.01)。流式细胞术检测结果显示，与对照组相比，2.5 mg/kg及以上剂量THI染毒能降低大鼠外周血中白细胞总数和T淋巴细胞的比例(P<0.01)，0.5 mg/kg及以上剂量组大鼠外周血中淋巴细胞数和B淋巴细胞的比例显著降低(P<0.05或P<0.01)，5 mg/kg的THI染毒可使脾脏中T细胞的比例下降(P<0.01)、NK细胞的比例升高(P<0.01)。T细胞亚群的分析结果显示，5 mg/kg的THI能降低大鼠外周血中Th细胞的比例(P<0.01)，0.5 mg/kg及以上剂量THI可使胸腺中Th细胞的比例升高(P<0.05或P<0.01)、CD4⁺CD8⁺双阳性T细胞的比例下降(P<0.05或P<0.01)，2.5 mg/kg及以上剂量THI可升高胸腺中CTL细胞的比例(P<0.01)。结论：THI经口暴露可损伤雌性大鼠的免疫系统，外周血中淋巴细胞数目减少是其敏感的效应指标，本研究条件下THI免疫毒性的未观察到有害作用水平(NOAEL)为0.1 mg/kg。

关键词: 2-乙酰基-4-四羟基-丁基咪唑, 大鼠, 免疫毒性, 淋巴细胞减少症

Abstract: OBJECTIVE：To investigate immunotoxicity of the main by-product 2-acetyl-4-tetrahydroxybutylimidazole (THI)，in the process of class Ⅲ caramel color production，on female rats. METHODS： 50 healthy adult female SD rats with SPF grade were randomly divided into 5 groups，10 rats in each group. They were given THI orally at doses of 0，0.1，0.5，2.5 and 5 mg/kg，respectively，continuously for 30 days. The followings were collected/evaluated：body weights，organ coefficients of thymus and spleen，histopathological evaluation of thymuses， number of white blood cells and various types of cells in peripheral blood， proliferation ability of spleen T lymphocytes，activities of NK cells，and flow cytometry evaluation of changes in the proportion of major immune cells in peripheral blood，thymus and spleen. RESULTS：THI exposure reduced the area ratio of thymus cortex/medulum and the proliferation ability of rat spleen T lymphocytes (with 2.5 and 5 mg/kg doses). The results of immunocytopathology showed that THI exposure at a dose of 2.5 mg/kg and above reduced the ratio of the total number of white blood cells and T lymphocytes in the peripheral blood and increase the ratio of NK cells in the spleen. The number of lymphocytes and the ratio of B lymphocytes in the peripheral blood were significantly reduced，and the ratio of T cells in the spleen was also reduced by the 5 mg/kg THI exposure. For the T cell subsets，5 mg/kg THI exposure reduced the ratio of Th cells in the peripheral blood. With doses of 0.5 mg/kg and above，THI increased the ratio of Th cells in the thymus and CD4⁺CD8⁺ double positive. The proportions of non-positive T cells were reduced. With doses of 2.5 mg/kg and above，THI increased the proportion of CTL cells in the thymus. CONCLUSION：Oral exposure to THI caused damage to the immune system of female rats. In addition， changes in the number of lymphocytes in peripheral blood and the proportion of thymus T cell subsets were sensitive indicators. Thus， the no observed adverse effect level of THI immunotoxicity (NOAEL) is 0.1 mg/kg.

Key words: 2-acetyl-4-tetrahydroxybutyl imidazole, rat, immunotoxicity, lymphopenia

中图分类号:

R994.4

袁悦, 原黎兰, 赵喆, 肖倩倩, 魏雪涛, 郝卫东. 2-乙酰基-4-四羟基-丁基咪唑对成年雌性大鼠的免疫毒性研究[J]. 癌变·畸变·突变, 2023, 35(2): 81-86.

YUAN Yue, YUAN Lilan, ZHAO Zhe, XIAO Qianqian, WEI Xuetao, HAO Weidong. Immunotoxicity of 2-acetyl-4-tetrahydroxybutyl imidazole on adult female rats[J]. Carcinogenesis, Teratogenesis & Mutagenesis, 2023, 35(2): 81-86.

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