Thyroid hormones modulate the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
Thyroid hormones modulate the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
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甲状腺激素调节 2,3,7,8-四氯二苯并-对二恶英 (TCDD) 的毒性。
DOI：
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
H. Greim
中科院分区：
文献类型：
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作者：
K. Rozman;T. Rozman;E. Scheufler;T. Pazdernik;H. Greim
本实验探讨甲状腺素（T4）和三碘甲状腺原氨酸（T3）对2,3,7,8-四氯二苯并-对二恶英（TCDD）毒性的作用。第一个实验是先前报道的研究的延续（Rozman et al., 1984）。将60只雄性Sprague-Dawley大鼠分为6组。4组大鼠均采用3mci Na131 l/kg大鼠进行甲状腺切除。5周后，2个甲状腺切除组和1个未甲状腺切除组大鼠分别给予100微克/kg体重的玉米油/丙酮TCDD， 3个相应组大鼠作为对照。给药后2 d及以后每7 d， 1个去甲状腺对照组和1个去甲状腺tcdd给药组给予T4 105微克/kg体重。监测死亡率和体重。TCDD的毒性过程在未去甲状腺和去甲状腺T4治疗的大鼠中相似，而在去甲状腺而未进行T4替代治疗的大鼠中则不同。TCDD给药后90 d，与未去甲状腺或去甲状腺t4处理大鼠相比，TCDD组大鼠死亡率仍较低，平均死亡时间延长（p < 0.01）。然而，在TCDD给药后第91天开始给药，在2周内，去甲状腺大鼠的最终死亡率与未去甲状腺或去甲状腺T4治疗的大鼠相同，这表明甲状腺激素调节了消耗综合征的时间过程，但不影响最终死亡率。去甲状腺的大鼠体重下降（约1 g/d）比未去甲状腺或去甲状腺的t4治疗大鼠（约8 g/d）慢得多。第二个实验采用第一个实验的三个载体对照组。未去甲状腺的对照组和去甲状腺的t4治疗对照组维持原样，而去甲状腺的对照组每天给予5微克/千克T3治疗。1个月后，每只大鼠在玉米油/丙酮中以100微克/千克的剂量给药TCDD。TCDD对未去甲状腺、去甲状腺T4处理和去甲状腺T3处理大鼠的毒性从死亡率、体重和摄取量的角度来看是相似的，表明T3和T4在TCDD毒性调节方面没有差异。
These experiments examine the role of thyroxine (T4) and triiodothyronine (T3) on the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The first experiment is continuation of a study reported previously (Rozman et al., 1984). In this experiment, 60 male Sprague-Dawley rats were divided into 6 equal groups. Four groups of rats were thyroidectomized by 3 mCi Na131 l/kg rat. Five weeks later 2 of the thyroidectomized and 1 of the nonthyroidectomized groups of rats received ip 100 micrograms TCDD/kg body weight in corn oil/acetone, whereas 3 corresponding groups of rats served as vehicle controls. Two days after dosing and every 7 d thereafter, 1 thyroidectomized control group and 1 thyroidectomized TCDD-dosed group were given ip 105 micrograms T4/kg body weight. Mortality and body weight were monitored. The course of TCDD toxicity was similar in nonthyroidectomized and thyroidectomized T4-treated rats but was different in thyroidectomized animals without T4 replacement therapy. At d 90 after TCDD dosage, mortality was still lower and the mean time to death was increased (p less than 0.01) in this group of rats compared to nonthyroidectomized or thyroidectomized T4-treated rats. However, administration of T4 starting at d 91 after dosing with TCDD resulted within 2 wk in the same final mortality in thyroidectomized rats as in nonthyroidectomized or thyroidectomized T4-treated animals, indicating that thyroid hormones modulate the time course of the wasting syndrome but do not affect the ultimate mortality figure. Body weight loss was much slower in thyroidectomized (approximately 1 g/d) than in nonthyroidectomized or thyroidectomized T4-treated rats (approximately 8 g/d). In the second experiment the three vehicle control groups of the first experiment were used. Nonthyroidectomized vehicle controls and thyroidectomized T4-treated controls were maintained as before, whereas thyroidectomized controls received T3 at 5 micrograms/kg daily. One month later each rat was dosed with TCDD at 100 micrograms/kg in corn oil/acetone. Toxicity of TCDD was similar in nonthyroidectomized, thyroidectomized T4-treated, and thyroidectomized T3-treated rats as judged by mortality, body weight, and food intake, indicating no difference between T3 and T4 in the modulation of TCDD toxicity.
给予 2,3,7,8-四氯二苯并-p-二恶英后，大鼠出现低甲状腺素血症和体温过低。
影响因子：
3.8
作者：
Potter,CL;Sipes,IG;Russell,DH
通讯作者：
Russell,DH