Rizza R A, Wahner H W, Spelsberg T C, Northcutt R C, Moses H L
J Nucl Med. 1978 May;19(5):458-63.
[131I] 19-iodocholesterol (I-131 C) correctly located adrenocortical adenomas in four patients who had no clinical or biochemical evidence of excessive steroid production. Three of the four "nonfunctioning" adenomas showed significant quantities of lipid histologically. To clarify the discordance between uptake and adrenal-steroid excretion, the subcellular location of I-131 C was studied. Normal rats and rats treated with ACTH or aminogluthimide (AG) were injected intravenously with I-131 C or [3H] cholesterol (H-3 C) and killed after three days. The homogenized adrenals were subjected to subcellular fractionation. Treatment with AG increased both the amount and the percentage of both I-131 C and H-3 C contained in the lipid fraction. ACTH treatment decreased H-3 C content but did not change I-131 C content in the lipid layer, suggesting an impairment of I-131 C mobilization from lipid droplets. The data demonstrate that excess steroid production is not necessary for I-131 C uptake and provide an explanation why certain biochemically nonfunctioning adrenocortical adenomas are visualized with I-131 C.
[131I]19 - 碘胆固醇（I - 131 C）在4例无类固醇分泌过多临床或生化证据的患者中准确地定位了肾上腺皮质腺瘤。这4例“无功能”腺瘤中的3例在组织学上显示有大量脂质。为了阐明摄取与肾上腺类固醇排泄之间的不一致性，对I - 131 C的亚细胞定位进行了研究。给正常大鼠以及用促肾上腺皮质激素（ACTH）或氨鲁米特（AG）处理过的大鼠静脉注射I - 131 C或[3H]胆固醇（H - 3 C），3天后处死。将匀浆后的肾上腺进行亚细胞分级分离。用AG处理可增加脂质部分中I - 131 C和H - 3 C的量及百分比。ACTH处理可降低脂质层中H - 3 C的含量，但不改变I - 131 C的含量，这表明I - 131 C从脂滴中的动员受损。这些数据表明，I - 131 C摄取并不一定需要过量的类固醇生成，并且解释了为什么某些生化上无功能的肾上腺皮质腺瘤能用I - 131 C显影。
