Synthesis and Evaluation of 24-(Isopropylseleno)chol-5-en-3β-ol

Article abstract of DOI:10.1021/jm00364a035

Selenium-75-labeled 24-(isopropylseleno)chol-5-en-3β-ol (4) has been prepared by reaction of sodium isopropyl<(75)Se>selenol (<(75)Se>2) with 3β-acetoxy-24-bromochol-5-ene (3).This new (75)Se-labeled adrenal imaging agent shows pronounced adrenal uptake in rats.The concentration of radioactivity in rat adrenals increased steadily from 1 to 24 h after injection and then decreased slowly over the 21-day period.After 3 days the adrenal/blood and adrenal/liver ratios were 85:1 and 32:1, respectively, which are sufficient for adrenal imaging by single photon techniques.After 6 h the adrenal/blood ratio was 17:1 and the adrenal/liver ratio was 7:1.We propose that these ratios are sufficiently high for positron emission tomography of the adrenals.The absorbed radiation dose values to human organs have been estimated for the (75)Se- and (73)Se-labeled agent.