Counsell R E, Schappa L W, Korn N, Huler R J
J Nucl Med. 1980 Sep;21(9):852-8.
This preliminary study was undertaken in order to explore possible methods for enhancing the target organ specificity of radioiodinated cholesterol. 19-[125I]cholesterol (IC) was rapidly incorporated and transported in high-density lipoproteins (HDL) following i.v. admnistration to rats, and thus behaved like cholesterol in this regard. Incorporation of IC into HDL (IC-HDL) before administration produced little change in the tissue distribution profile except for a reduction in the amount of radioactivity appearing in the thyroid. This suggested that the lipoprotein carrier may have afforded protection from metabolic dehalogenation of IC. When rats were pretreated with 4-aminopyrazolo-(3,4d)-pyrimidine to drastically reduce the circulating lipoprotein levels, a fourfold enhancement in adrenal uptake was observed following administration of IC-HDL. This finding was consistent with the current view that the rat adrenal contains high-affinity and saturable receptors for HDL.
进行这项初步研究是为了探索增强放射性碘化胆固醇靶器官特异性的可能方法。静脉注射给大鼠后，19-[¹²⁵I]胆固醇（IC）迅速被高密度脂蛋白（HDL）摄取并转运，因此在这方面表现得与胆固醇相似。给药前将IC掺入HDL（IC-HDL），除甲状腺中出现的放射性量减少外，组织分布情况几乎没有变化。这表明脂蛋白载体可能为IC提供了免受代谢脱卤的保护。当用4-氨基吡唑并-(3,4-d)-嘧啶预处理大鼠以大幅降低循环脂蛋白水平时，给予IC-HDL后观察到肾上腺摄取增加了四倍。这一发现与目前认为大鼠肾上腺含有HDL高亲和力和可饱和受体的观点一致。
