Jones R E, Aulerich R J, Ringer R K
Texas Instruments, Dallas 75265.
Biomed Environ Sci. 1993 Mar;6(1):81-8.
We fed adult mink diets containing supplemental iodine, from 0 to 320 ppm, for one or seven months prior to breeding. Blood samples collected from the adults and their offspring (kits) at 4 wk post-partum were assayed for total thyroxine (T4), triiodothyronine (T3), reverse T3 (rT3), and T4-binding indices. As expected T4 concentrations of the adult and kit mink varied inversely with the level of supplemental iodine. In addition, T3 and rT3 concentrations decreased gradually in kits from the long-term experiment in response to the increased dietary iodine of the dams. T3 concentrations of kits from dams fed iodine short-term decreased markedly while rT3 concentrations were elevated greatly in response to increased dietary iodine of the dam. These decreases in hormone levels are due to serum iodine blocking the thyroid uptake of iodine and subsequent decrease of hormone synthesis. Excess iodine may also block the effect of thyroid stimulating hormone. The T4-binding indices of the adults, in general, were depressed, while the T4-binding indices of the kits were more variable. These effects are probably due to fluctuations in thyroglobulin.
在繁殖前的1个月或7个月期间，我们给成年水貂喂食含0至320 ppm补充碘的日粮。在产后4周从成年水貂及其后代（幼崽）采集血样，检测总甲状腺素（T4）、三碘甲状腺原氨酸（T3）、反三碘甲状腺原氨酸（rT3）和T4结合指数。正如预期的那样，成年水貂和幼崽水貂的T4浓度与补充碘水平呈负相关。此外，在长期实验中，幼崽的T3和rT3浓度随着母貂日粮碘含量的增加而逐渐降低。短期喂食碘的母貂所产幼崽的T3浓度显著降低，而rT3浓度则因母貂日粮碘含量增加而大幅升高。这些激素水平的降低是由于血清碘阻断了甲状腺对碘的摄取以及随后激素合成的减少。过量的碘也可能阻断促甲状腺激素的作用。一般来说，成年水貂的T4结合指数降低，而幼崽的T4结合指数变化更大。这些影响可能是由于甲状腺球蛋白的波动所致。
