Dang J, Miquelis R, Bastiani P, Simon C
Acta Endocrinol (Copenh). 1975 Jul;79(3):459-73. doi: 10.1530/acta.0.0790459.
In a previous study (Simon et al. 1971) a procedure for the preparation and separation of iodinated particles was described in the rat. The present paper deals with further investigations on the nature of these particles. Acid phosphatase and iodine are conjointly sedimentable and display a latency that is unmasked on dilution in a hypo-osmotic medium and under acidification to pH 5.0. These properties together with the sensitivity to Triton X-100 are best accounted for by assuming that iodinated particles of the thyroid gland are lysosomes. Part of the particulate iodine is soluble in n-butanol (BEI fraction). The existence of this BEI fraction demonstrates that hydrolysis of thyroglobulin occurs within the particles which thus exhibit an acid protease activity. Both the sedimentable iodine pool and acid phosphatase are increased under TSH stimulation and decreased after thyroxine treatment. In addition, the general activity of the iodinated particles is dependent on the daily iodine intake as shown by the variation of their iodine pool, acid phosphatase activity and BEI fraction with the iodine diet. It is concluded that iodinated particles of the thyroid gland are secondary lysosomes which participate in iodine secretion under TSH control. By in vitro treatment with destabilizing media or after in vivo treatment with thyroxine, iodinated particles exhibit a parallel loss of iodine and acid phosphatase. After a short-term TSH treatment in vivo, their iodine pool is more increased than their acid phosphatase activity. It is concluded that, at least in the normal rat thyroid, iodinated particles are essentially secondary lysosomes; true colloid droplets actually accumulate only after sufficient TSH stimulation.
在之前的一项研究（西蒙等人，1971年）中，描述了在大鼠体内制备和分离碘化颗粒的方法。本文对这些颗粒的性质进行了进一步研究。酸性磷酸酶和碘可共同沉淀，并表现出一种潜伏期，在低渗介质中稀释并酸化至pH 5.0时这种潜伏期会被暴露出来。这些特性以及对 Triton X - 100 的敏感性，通过假设甲状腺的碘化颗粒是溶酶体来解释最为合理。部分颗粒碘可溶于正丁醇（BEI 部分）。这种 BEI 部分的存在表明甲状腺球蛋白的水解发生在颗粒内，因此颗粒表现出酸性蛋白酶活性。在促甲状腺激素（TSH）刺激下，可沉淀碘池和酸性磷酸酶均增加，而在甲状腺素处理后则减少。此外，碘化颗粒的总体活性取决于每日碘摄入量，这可通过其碘池、酸性磷酸酶活性和 BEI 部分随碘饮食的变化得以体现。结论是，甲状腺的碘化颗粒是次级溶酶体，在 TSH 的控制下参与碘的分泌。通过用去稳定介质进行体外处理或在体内用甲状腺素处理后，碘化颗粒表现出碘和酸性磷酸酶的平行损失。在体内进行短期 TSH 处理后，它们的碘池增加量比酸性磷酸酶活性增加量更多。结论是，至少在正常大鼠甲状腺中，碘化颗粒本质上是次级溶酶体；真正的胶体小滴实际上仅在足够的 TSH 刺激后才会积累。
