title: Synthesis and evaluation of 24-(isopropyl[75Se]seleno)chol-5-en-3 beta-ol.
abstract: Selenium-75-labeled 24-(isopropylseleno)chol-5-en-3 beta-ol (4) has been prepared by reaction of sodium isopropyl-[75Se]selenol [( 75Se]2) with 3 beta-acetoxy-24-bromochol-5-ene (3). This new 75Se-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 75Se- and 73Se-labeled agent.
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D002770:Cholenes / Q000138:chemical synthesis* / Q000378:metabolism; D005260:Female; D007202:Indicators and Reagents; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D013058:Mass Spectrometry; D016566:Organoselenium Compounds; D010053:Ovary / Q000378:metabolism; D011868:Radioisotopes; D011877:Radionuclide Imaging / Q000379:methods*; D051381:Rats; D012643:Selenium / Q000138:chemical synthesis* / Q000378:metabolism; D013055:Spectrophotometry, Infrared; D014018:Tissue Distribution
chemical_list: D002770:Cholenes; D007202:Indicators and Reagents; D016566:Organoselenium Compounds; D011868:Radioisotopes; C039374:24-(isopropylseleno)chol-5-en-3-ol; D012643:Selenium