16 alpha-Iodo-testosterone: chemical synthesis and evaluation as a potential radiopharmaceutical.
The chemical synthesis and characterization, including 1H NMR, of 16 alpha-iodo-androstenedione and 16 alpha-iodo-testosterone are described. Each has been synthesized with 125I and tested in rats in vivo for accumulation in androgen dependent tissues over a 24 hr time course. Neither compound was accumulated in prostate against the blood gradient of normal or 24 hr castrate animals. The metabolism, subcellular distribution and binding of 16 alpha-[125I]iodo-testosterone to protein in prostate has also been examined. By comparison with data obtained after the administration of [3H]testosterone we conclude that the failure of this iodinated androgen to accumulate in androgen dependent tissues arises because of its low binding affinity for receptor protein.
D000818:Animals; D007457:Iodine Radioisotopes; D007553:Isotope Labeling / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D011467:Prostate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011944:Receptors, Androgen / Q000378:metabolism; D013739:Testosterone; D014018:Tissue Distribution
D007457:Iodine Radioisotopes; D011944:Receptors, Androgen; D013739:Testosterone