Potential organ- or tumor-imaging agents XX: Ovarian imaging with 19-radioiodinated cholesterol.
Cholesterol is stored in the ovaries where it is a precursor in the biosynthesis of the female sex hormones progesterone and estradiol. The purpose of this study was to determine whether a radioiodinated analog of cholesterol, 125I-labeled 19-iodocholesterol, would mimic cholesterol in this capacity and thus offer a means for imaging the ovaries of intact animals. Aside from the thyroid, the adrenal glands and ovaries of the female rat retained the highest levels of radioactivity at 4 days following the intravenous administration of 125I-labeled 19-iodocholesterol. Moreover, the levels of radioactivity were sufficient to obtain clear images of the adrenal glands and ovaries with a small animal scanner. Folch analysis of these tissues revealed that > 80% of the radioactivity was associated with the sterol ester fraction.