EFFECT OF STRUCTURAL MODIFICATIONS ON THE ADRENAL UPTAKE OF STEROIDS LABELED IN THE SIDE-CHAIN WITH TELLURIUM-123M

  • 1 January 1980
    • journal article
    • research article
    • Vol. 21  (3) , 258-263
Abstract
A series of structurally modified steroids labeled in the side chain with 123mTe was prepared and tested in rats to determine the critical structural features required for maximal adrenal uptake of this new class of potential adrenal-imaging agents. 123mTe steroids investigated contained structural modifications of both the nucleus and side chain. Tissue distribution experiments and rectilinear scans indicated that 23-(isopropyl telluro)-24-nor-5.alpha.-cholan-3.beta.-ol (saturated nucleus), and 24-(isopropyl telluro)-chol-5-en-3.beta.-ol (nuclear double bond) showed pronounced adrenal uptake after 1 day, with adrenal-to-liver ratios of 41 and 27, respectively. A combination of structural features apparently is required for significant adrenal uptake of steroids labeled in the side chain with 123mTe. The structural requirements include a trans ring structure, an equatorial C-3 hydroxyl group and a 17.beta. side chain of moderate length.