Shah N M, Eskin B A, Krouse T B, Sparks C E
Proc Soc Exp Biol Med. 1986 Mar;181(3):443-9. doi: 10.3181/00379727-181-42279.
Iodide organification by rat mammary glands was studied during the trimesters of pregnancy and early postpartum period. Organification was followed by measuring trichloroacetic acid (TCA) precipitation of delipidated tissue homogenates. The radiolabeled material was sensitive to proteolytic cleavage by a bacterial protease indicating that the 125I was protein-bound. Gel filtration column chromatography in the presence of sodium dodecyl sulfate (SDS) of delipidated mammary tissue homogenates of pregnant and postpartum rats reproducibly resolved several iodoproteins from free iodide. The Kav value for each iodoprotein peak was calculated and was used to estimate each subunit molecular weight which averaged 37,500, 25,100, and 8500. Another iodoprotein with a very large subunit molecular weight of greater than 300,000 was also detected in mammary tissue. Incorporation of 125I-iodide into the three smaller iodoproteins increased logarithmically from the start of the second trimester of pregnancy through the early postpartum period when approximately 20% of the total 125I uptake by mammary tissue was incorporated into protein. Hyperplasia, acinar development, and intracytoplasmic vacuolization of mammary tissue correlated with the increased incorporation of 125I-iodide into these iodoproteins. The characterization and quantitation of specific iodoproteins in mammary tissue may be important as organification of iodide is believed to be a marker for normal hormone-responsive cells.
在大鼠孕期各阶段及产后早期，对其乳腺的碘有机化过程进行了研究。通过测量脱脂组织匀浆的三氯乙酸（TCA）沉淀来追踪碘有机化情况。放射性标记物质对细菌蛋白酶的蛋白水解切割敏感，这表明125I与蛋白质结合。在十二烷基硫酸钠（SDS）存在的情况下，对怀孕和产后大鼠的脱脂乳腺组织匀浆进行凝胶过滤柱层析，可重复性地从游离碘化物中分离出几种碘蛋白。计算了每个碘蛋白峰的Kav值，并用于估算每个亚基的分子量，其平均值分别为37,500、25,100和8500。在乳腺组织中还检测到另一种亚基分子量非常大（大于300,000）的碘蛋白。从妊娠中期开始到产后早期，125I-碘化物掺入三种较小的碘蛋白的量呈对数增加，此时乳腺组织摄取的125I总量中约20%掺入了蛋白质。乳腺组织的增生、腺泡发育和胞浆内空泡化与125I-碘化物掺入这些碘蛋白的增加相关。乳腺组织中特定碘蛋白的表征和定量可能很重要，因为碘的有机化被认为是正常激素反应性细胞的一个标志。
