De Heer C, Schuurman H J, Vos J G, Van Loveren H
Laboratory for Pathology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
Chemosphere. 1994 Nov-Dec;29(9-11):2295-9. doi: 10.1016/0045-6535(94)90397-2.
Atrophy of the thymus and thymic lymphodepletion occurs after exposure to sublethal doses of TCDD. Previous studies using high doses of TCDD (150 micrograms/kg) have indicated a preferential lymphodepletion of the thymus cortex on day 4 after a single oral intubation. Here we describe the effects of a single oral intubation of lower dose levels of TCDD (1, 5, and 25 micrograms/kg) on thymic weights and thymocyte subpopulations in Wistar rats on day 4 after exposure. A single administration of 1 micrograms/kg TCDD induced a significant reduction in the number of immature CD4+CD8+ double-positive (DP) thymocytes. At this time point the numbers of mature CD3high medullary thymocytes were not affected at any dose level tested. We conclude that also lower dose levels of TCDD induce thymic atrophy via a preferential lymphodepletion of the thymus cortex.
暴露于亚致死剂量的2,3,7,8-四氯二苯并对二恶英（TCDD）后会出现胸腺萎缩和胸腺淋巴细胞耗竭。先前使用高剂量TCDD（150微克/千克）的研究表明，单次经口插管后第4天胸腺皮质出现优先淋巴细胞耗竭。在此，我们描述了在暴露后第4天，单次经口给予低剂量水平的TCDD（1、5和25微克/千克）对Wistar大鼠胸腺重量和胸腺细胞亚群的影响。单次给予1微克/千克TCDD可导致未成熟CD4 + CD8 +双阳性（DP）胸腺细胞数量显著减少。在这个时间点，任何测试剂量水平下成熟的CD3高表达髓质胸腺细胞数量均未受影响。我们得出结论，较低剂量水平的TCDD也会通过胸腺皮质的优先淋巴细胞耗竭诱导胸腺萎缩。
