iodine I 131 iodocholesterol

A radioiodine-labeled cholesterol analogue with diagnostic imaging activity upon scintigraphy. Upon administration, iodine I 131 iodocholesterol accumulates in tissues where steroid hormones are produced, including the adrenal glands and, to a lesser extent, the ovaries and the testes. After binding to low-density lipoprotein (LDL) receptors on adrenocortical cells, this agent is internalized. As cholesterol is the precursor for all adrenocortical steroid hormones, areas of hormonal hypersecretion, can be visualized using scintigraphy and the adrenocortical function can be assessed.