Thunberg T, Håkansson H
Arch Toxicol. 1983 Jul;53(3):225-33. doi: 10.1007/BF00316506.
Vitamin A (retinol) status and the effect of a single oral dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 10 micrograms X kg-1, on vitamin A in the liver and serum, and on the hepatic UDP-glucuronosyltransferase (UDPGT) (EC 2.4.1.17) activity, were studied in heterozygous (GW) and homozygous (GG) Gunn rats. 1) Data from vitamin A analyses demonstrate that the amount of vitamin A stored in the liver of untreated Gunn rats is of the same magnitude as that of Sprague-Dawley rats. 2) The retinol content in the liver of both GG and GW rats was reduced to about 50% by TCDD-treatment. 3) Retinol levels in serum were found to be variable and no significant effect due to TCDD could be observed. 4) No correlation between the TCDD-induced reduction of vitamin A and the induction of UDPGT activity by TCDD could be demonstrated in this study. The vitamin A reduction caused by TCDD was considerably less in the Gunn rat than in the Sprague-Dawley rat, and the results indicate that the Gunn rat is more resistant to TCDD than other strains of rat. TCDD-induced reduction of liver vitamin A seems to some extent to correlate with TCDD-toxicity in different strains of rat. The specific properties of the Gunn rat and its relatively high resistance to TCDD make it a valuable tool in studies about the mechanism of TCDD-toxicity.
在杂合子（GW）和纯合子（GG）Gunn大鼠中，研究了维生素A（视黄醇）状态以及单次口服剂量为10微克/千克的2,3,7,8-四氯二苯并对二恶英（TCDD）对肝脏和血清中维生素A以及肝脏UDP-葡萄糖醛酸基转移酶（UDPGT）（EC 2.4.1.17）活性的影响。1）维生素A分析数据表明，未处理的Gunn大鼠肝脏中储存的维生素A量与Sprague-Dawley大鼠的相同。2）TCDD处理使GG和GW大鼠肝脏中的视黄醇含量均降低至约50%。3）发现血清中的视黄醇水平存在变化，未观察到TCDD产生的显著影响。4）在本研究中，未证明TCDD诱导的维生素A减少与TCDD诱导的UDPGT活性之间存在相关性。TCDD对Gunn大鼠造成的维生素A减少比Sprague-Dawley大鼠少得多，结果表明Gunn大鼠比其他品系的大鼠对TCDD更具抗性。TCDD诱导的肝脏维生素A减少在一定程度上似乎与不同品系大鼠的TCDD毒性相关。Gunn大鼠的特殊性质及其对TCDD相对较高的抗性使其成为研究TCDD毒性机制的有价值工具。
