metribolone and Disorders-of-Sex-Development

We have used 5 alpha-dihydrotestosterone (DHT) and two synthetic, non-metabolizable androgens, methyltrienolone (MT) and mibolerone (MB), to study intact genital skin fibroblasts from four subjects with familial incomplete androgen resistance. In each, the free androgen receptor has normal binding capacity at 37 degrees C and normal half-lives at 37-43 degrees C. In three the mutant receptor misbehaves in a pattern that is ligand-specific and temperature-dependent. At 37 degrees C the equilibrium (Kd) and non-equilibrium (k) dissociation constants, and the ability to augment binding activity during prolonged exposure to androgen, are impaired with DHT, but not with MT; with MB, only the k is abnormal. Mutant MT-receptor complexes dissociate normally even at 42 degrees C; yet, in cells post-incubated at 42 degrees C with cycloheximide and a saturating concentration of ligand, their pool size decays in the rank order, MT greater than MB greater than normal. This measure of lability is nonlinear as a semilogarithmic function of time; it varies directly with temperature and the concentration of cycloheximide, but inversely with that of ligand. Thus, MT and MB evoke distinct forms of thermal dysfunction from the androgen receptor in ligand-sensitive androgen resistance. This observation will help to elucidate the combinatorial properties of normal androgen-receptor complexes that enable them to regulate gene transcription differentially in various androgen target tissues.

Topics: Androgens; Cycloheximide; Dihydrotestosterone; Disorders of Sex Development; Drug Resistance; Estrenes; Fibroblasts; Genitalia, Male; Half-Life; Humans; Kinetics; Male; Metribolone; Mutation; Nandrolone; Receptors, Androgen; Skin; Temperature

We have studied a child with posterior labial fusion, clitoral phallus, female urethra, and a short, blind vagina born to a mother with decreased axillary and pubic hair. Her karyotype is 46,XY. At 2 yr of age, the child's basal level of plasma testosterone was less than 0.35 nM and after human chorionic gonadotropin stimulation, it rose to 2.6. Testis and epididymis histology were normal. Her cultured genital (labial) skin fibroblasts have normal testosterone 5 alpha-reductase activity, and metabolize 5 alpha-dihydrotestosterone (DHT) normally, but they do not augment (up-regulate) their basal androgen-receptor binding activity during prolonged incubation with DHT. With DHT, the androgen receptor in her genital skin fibroblasts has a normal binding capacity (maximum binding capacity = 25 fmol/mg protein), but an increased rate constant of dissociation (k = 11.6 X 10(-3) min-1; normal, 6 +/- 1.2 (+/- SD)), and a decreased apparent equilibrium binding affinity (Kd = 0.6 nM; normal, 0.22 +/- 0.09) that is evident in the results of 2-h assays but not of those lasting 0.5 h. With the synthetic androgen, methyltrienolone, all three binding properties of the receptor are normal, and her receptor activity up-regulates normally. We interpret these results to mean that the subject has a ligand-selective defect in the time-dependent transformation of initial, low-affinity androgen-receptor complexes to serial states of higher affinity, presumably as the result of a structural mutation at the X-linked locus that encodes the androgen receptor protein.

Topics: Cells, Cultured; Child, Preschool; Dihydrotestosterone; Disorders of Sex Development; Estrenes; Female; Fibroblasts; Genitalia, Female; Humans; Metribolone; Mutation; Receptors, Androgen; Receptors, Steroid; Skin; Testosterone Congeners

We have studied various properties of the binding of 5 alpha-dihydrotestosterone (DHT) or the synthetic, nonmetabolizable androgen methyltrienolone (R1881; 17 beta-hydroxy-17 alpha-methylestra-4,9,11-trien-3-one) to the androgen receptor of genital skin fibroblasts (GSF) from controls and a subject with familial, receptor-positive, partial androgen insensitivity. The mutant cells form R1881-receptor complexes that dissociate 7 times more rapidly than normal at 30 degrees C, and they do not increase their specific R1881-receptor activity in response to a 72-hr period of incubation with R1881, whereas the cells from normal individuals do so two- to three-fold. As previously reported [Pinsky et al, 1981; Kaufman et al, 1981], the mutant cells have similar abnormalities with DHT as with R1881. When the patient's cells are incubated for 120 min with varying concentrations (0.05-3 nM) of R1881 or DHT, Scatchard analysis shows that their androgen-receptor activity has an apparent equilibrium dissociation constant (Kd) for each ligand that is six-fold greater than that of normal cells (approximately 0.2 nM). Normal GSF have higher, more variable values of Kd (0.3-1.8 nM) for either ligand after 30 compared to 120 min of incubation, and the 60-min values are intermediate. This explains why we previously reported that the patient's cells had a 30-min Kd for DHT in the normal range [Pinsky et al, 1981]. Sucrose gradient centrifugation of mutant GSF cytosol incubated with DHT in the presence of 10 mM sodium molybdate yields a normal 6.5-8S peak of DHT-receptor complexes. From these data we conclude that normal GSF form initial, low-affinity androgen-receptor complexes that are transformed into one (or more) higher-affinity (? activated) states by a process that depends on time and initial concentration of androgen; the subject's GSF can form low-affinity androgen-receptor complexes but cannot generate the normal high-affinity state of the complexes, and this lack precludes augmentation of their androgen-receptor activity in response to prolonged incubation with either androgen; and failure of molybdate to stabilize the androgen-receptor activity in GSF cytosol is not a more sensitive indicator of structurally altered androgen-receptor proteins than are other qualities described heretofore.

Topics: Adolescent; Child; Dihydrotestosterone; Disorders of Sex Development; Estrenes; Fibroblasts; Follow-Up Studies; Gene Expression Regulation; Gynecomastia; Humans; Kinetics; Male; Metribolone; Receptors, Androgen; Receptors, Steroid; Testosterone

We have studied a kindred in which two parts of siblings, maternal first cousins, have a form of "minimal" androgen insensitivity that permits morphogenesis of unambiguous male external genitalia, but interferes with normal virilization at puberty. All four had gynecomastia that required reductive surgery. Apart from this common phenotype, they varied considerably in the temporal and regional aspects of their subvirilization and appreciably in their androgenic responsiveness to pharmacological doses of testosterone. The cultured genital skin fibroblasts from one set of siblings have an androgen-receptor activity with the following properties: (1) a normal maximum-binding capacity (Bmax) with 5 alpha-dihydrotestosterone (DHT), or the synthetic androgen, methyltrienolone (MT; R1881) as ligand; (2) a higher than normal apparent equilibrium dissociation constant (Kd) for DHT (0.77 nM) but not for MT; and (3) an elevated dissociation rate (k) of DHT-receptor (0.013 min-1, 37 degrees C), but not MT-receptor, complexes within intact cells. In addition, prolonged incubation with MT, but not DHT, augments the specific androgen-binding activity of the mutant cells as much as that of the controls. Normal cells yield lower values of apparent Kd for DHT (0.1-0.3 nM) after 2- than after 0.5-hr incubation (0.3-1.8 nM), and 1-hr values are intermediate. This occurs despite concurrent catabolic consumption of DHT from the medium and is considered to reflect transformation of initial, low-affinity DHT-receptor complexes to subsequent, higher-affinity states by a process that depends on time and initial ligand concentration. The mutant complexes described here can readily attain the highest state of affinity with MT, but have an impeded, variably expressed ability to do so with DHT. These findings suggest that a structural mutation at the X-linked locus that encodes the androgen-receptor protein is responsible for its androgen-selective dysfunction. Synthetic, nonhepatotoxic androgens, with corrective effects in vitro comparable to those of MT, may be therapeutically useful for these subjects.

Topics: 3-Oxo-5-alpha-Steroid 4-Dehydrogenase; Adolescent; Adult; Androgen-Insensitivity Syndrome; Androgens; Cells, Cultured; Dihydrotestosterone; Disorders of Sex Development; Estrenes; Fibroblasts; Humans; Kinetics; Male; Metribolone; Mutation; Pedigree; Receptors, Androgen; Receptors, Steroid; Scrotum; Skin

Enzyme kinetics of 5 alpha-reductase were compared in cultured genital skin fibroblasts taken from 6 control subjects and from an affected subject with 5 alpha-reductase deficiency in whom the diagnosis was established on hormonal grounds. The Km value for testosterone in the mutant enzyme was extremely high (1,427 vs. 185-417 nmol/l in controls). in the mutant enzyme was extremely high (1,427 vs 185-417 nmol/l in controls). A A mutant but stable enzyme with reduced affinity to steroid substrate is reported.

Topics: 3-Oxo-5-alpha-Steroid 4-Dehydrogenase; Androgen-Insensitivity Syndrome; Cells, Cultured; Child, Preschool; Chorionic Gonadotropin; Disorders of Sex Development; Estrenes; Female; Fibroblasts; Genitalia; Hot Temperature; Humans; Hydrogen-Ion Concentration; Male; Metribolone; Oxidoreductases; Testosterone

The practical application of a simple, reproducible androgen receptor assay using dispersed fibroblasts is described for the investigation of patients with the androgen insensitivity syndrome (AIS). The concentration of androgen receptors (Bmax) in genital skin fibroblasts derived from normal subjects is 814 +/- 168 X -18 moles/microgram DNA (mean +/- SD) and the binding affinity (Kd) is 0.91 +/- 0.26 X 10(-10)M at 37 degrees C, using [3H]-5 alpha-dihydrotestosterone (DHT) as the labelled ligand. Studies in patients with phenotypic signs of complete or partial AIS showed either absent (receptor-negative), decreased (receptor-deficient) or normal/increased (receptor-positive) specific binding of DHT to the receptor. In some mutant cell lines, there was evidence of thermolability and increased rate constant of dissociation of the androgen-receptor complex, suggesting a possible structural abnormality of the receptor protein. This simple receptor assay can be used to delineate quantitative and qualitative defects of the androgen receptor in a significant number of patients with a wide spectrum of phenotypic abnormalities associated with androgen resistance.

Topics: Adolescent; Cell Line; Cell Nucleus; Child; Child, Preschool; Dihydrotestosterone; Disorders of Sex Development; DNA; Estrenes; Female; Fibroblasts; Hot Temperature; Humans; Infant; Kinetics; Male; Metribolone; Receptors, Androgen; Receptors, Steroid; Skin

Topics: Adolescent; Adult; Age Factors; Aged; Child; Child, Preschool; Cytosol; Dihydrotestosterone; Disorders of Sex Development; Estrenes; Female; Genitalia; Humans; Infant; Infant, Newborn; Male; Metribolone; Middle Aged; Receptors, Androgen; Receptors, Steroid; Sex Factors; Skin

We have found a specific binding protein for synthetic progestins 6,7-[3H]methyltrienolone (R1881) and 17,21-dimethyl-19-norpregna-4,9-diene-3,20-dione (R5020) and in the testis cytosol from three "sisters" with the complete form of the testicular feminization syndrome. The binding component sediments in the 8S region of sucrose gradients. It is saturable. The apparent affinity constant (Ka) for R5020 was determined in two cases and found to be 1.8 and 0.6 X 10(8) M-1. The number of binding sites calculated from Scatchard plots is relatively high: 572 and 826 fmol/mg protein. Competition studies indicate that this putative receptor is specific for natural and synthetic progestins but not for 5 alpha-dihydrotestosterone and cortisol. Similar progestin binding could not be found in normal human and rat testes.

Topics: Adult; Animals; Disorders of Sex Development; Estrenes; Female; Feminization; Follicle Stimulating Hormone; Humans; Luteinizing Hormone; Male; Metribolone; Middle Aged; Promegestone; Rats; Rats, Inbred Strains; Receptors, Progesterone; Testis; Testosterone; Testosterone Congeners