Synthesis of potential antiprogestins II

Alkylated derivatives of 17-acetoxyprogesterone were prepared in order to test the hypothesis that bulky groups in certain positions of the steroid molecule have the effect of transforming progestogens into antiprogestogens. These groups might exert binding influence outside the area occupied by progesterone itself. The compounds were tested for competitive affinity against tritiated progesterone and receptor from rabbit uterus cytosol. The low affinity of all derivatives makes it unlikely that they would be active as antiprogestational agents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23258/1/0000191.pd

A specific radioimmunoassay for androstenedione with reduced bridge-binding

Antibody used in a steroid radioimmunoassay raised against a steroid hapten-carrier protein conjugate may recognize both the hapten and the chemical bridge to the protein. Use of the same bridge in the radioisotopic label may lead to higher affinity binding to the label than to the native steroid. Inhibition curves under these conditions are shallow and generally not acceptable for radioimmunoassay procedures. We have developed a radioimmunoassay for androstenedione that employs different bridges at the 11[beta] position of the steroid for the protein conjugate and label. The resulting assay has greatly reduced bridge-binding, has an acceptable slope for the standard curve and is very specific as evidenced by low crossreactivies to other steroids.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24709/1/0000130.pd

Potential tumor- or organ-imaging agents. 28. Radioiodinated esters of cholesterol and pregnenolone

Previous studies had shown radioiodinated esters of cholesterol and pregnenolone to accumulate in steroid-secreting tissues of the rat. This was particularly true for radioiodinated iopanoate esters. The present study was undertaken to examine the effect of the iopanoyl amino group on the tissue distribution of these esters. While the tissue distribution profiles for cholesteryl iopanoate and the desamino analog (III) were somewhat comparable, such was not the case for the corresponding esters of pregnenolone. Moreover, this subtle structural change of removing the amino group was observed to affect the stability of the esters to hydrolysis. This conclusion is in accordance with the observation that the tissue distribution profiles for the free acids I and II are not significantly different from each other. These studies serve to demonstrate that relatively minor modifications of the acyl moiety have a profound effect on both the uptake and distribution of these sterol esters in various tissues.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26697/1/0000245.pd

Lack of hydroxylation-induced migration with 4-iodophenylalanine

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32730/1/0000098.pd

Synthesis of β‐ 3 H‐mitotane for use in a rapid assay for mitotane metabolism

A 3 H + ‐release method has been developed for the assay of β‐hydroxylation of the adrenolytic drug mitotane. β‐ 3 H‐mitotane was synthesized by the reduction of 1‐(2‐chlorophenyl)‐1‐(4‐chlorophenyl)‐2,2,2‐trichloroethane by an aluminium‐Hg 2 Cl 2 couple in the presence of 3 H 2 O. For β‐hydroxylation of mitotane, the 3 H + ‐release assay is more efficient and sensitive than a method utilizing 14 C‐mitotane and chromatographic separation of metabolites by HPLC. The 3 H + ‐release assay has been used to evaluate the ability of adrenal tumors to metabolize mitotane via the β‐ hydroxylation route.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90382/1/2580360204_ftp.pd

A chemical approach to solving bridging phenomena in steroid radioimmunoassays

Steroid radioimmunoassays (RIA) employ antibodies raised against a carrier protein-steroid conjugate. Individual antibodies may recognize the steroid, the protein or the chemical bridge used to Join them together. Use of the same bridge In the tracer results in higher affinity binding of the tracer than the native ligand which in turn results in a loss of sensitivity and precision. We have greatly reduced bridge-binding In a RIA for androstenedione. Conjugates and radioiodinated labels were prepared with either an ester op ether chemical bridge. By using an antibody and the corresponding label with the heterologous bridge very sensitive assays were obtained.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24289/1/0000555.pd

Tumor localizing agents. IX. Radioiodinated cholesterol

19-Iodocholesterol-125I was synthesized for study as a possible agent for photoscanning the adrenal gland and associated tumors. In contrast to previous radioiodinated steroids, it was found to be much less prone to rapid in vivo deiodination. Preliminary tissue distribution studies and biochemical analyses have revealed a marked similarity in the behavior of the radioiodinated derivative with the natural steroid. The concentration of radioactivity in the adrenal cortex of dogs at 48 hours was found to greatly exceed that found in other organs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32739/1/0000108.pd

Comparison of the adrenalytic activity of mitotane and a methylated homolog on normal adrenal cortex and adrenal cortical carcinoma

Mitotane is an important adrenalytic drug for the treatment of adrenal cancer whose use is limited by toxicity. Reports from another laboratory indicated that a methylated homolog of Mitotane (Mitometh) tested in guinea pigs possessed comparable adrenalytic activity but was less toxic than Mitotane. This observation prompted us to undertake a comparative study of these two drugs on the basis that Mitometh may be a superior agent for the treatment of adrenal cancer. Preliminary studies in guinea pigs failed to show a significant adrenalytic effect for either Mitotane or Mitometh. Thus, we extended the study to 13 mongrel dogs weighing 12–15 kg that were treated daily with Mitometh or Mitotane (50–100 mg/kg) for 6 or 12 days. Cortisol decreased to undetectable levels and adrenocorticotropic hormone (ACTH) rose to 10 times the baseline levels within 72 h in Mitotane-treated animals. Despite the achievement of similar drug levels, Mitometh treatment in dogs failed to suppress cortisol or increase ACTH. To determine whether these differences were due to differences in bioavailability, we measured the relative concentration of Mitotane and Mitometh in homogenates of adrenal cortex obtained from Mitotane- and Mitometh-treated dogs. The adrenal concentration of Mitometh determined in Mitometh-treated dogs was 5 times higher than the concentration of Mitotane measured in Mitotane-treated animals. Whereas the adrenal glands of Mitotane-treated dogs showed hemorrhage and necrosis, the Mitometh-treated animals showed no adrenal damage. Despite the lack of adrenalytic activity, Mitometh maintained its toxicity as demonstrated by microscopic evidence of hepatic necrosis and an increase in hepatic enzymes. The adrenalytic effects of both agents was also studied in vitro using a human functioning adrenal cortical carcinoma cell line. NCI-H295. Whereas Mitotane strongly suppressed cell growth, Mitometh had a weaker effect. We conclude that Mitometh is not likely to be effective in the therapy of adrenal cancer. Moreover, the results of this study are supportive of the view that metabolic transformation of Mitotane is in some way linked to its adrenalytic action.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46925/1/280_2004_Article_BF00685036.pd

Radioiodination via isotope exchange in pivalic acid

A variety of benzoic and aryl aliphatic mono and polyiodinated acids and esters (sterol, triglyceride) were radioiodinated in 55-99% radiochemical yield by isotope exchange with Na 125I in a melt of pivalic acid. In general, the reaction was complete in 1 h at 155[deg]C with little or no substrate decompostion. High specific activity studies afforded 125I-labeled iopanoic acid with a specific activity of over 700 Ci/mmol.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26445/1/0000533.pd