Androgen Derivatives Research Articles

Androgens and Androgen Derivatives: Science, Myths, and Theories: Explored From a Special Operations Perspective.

Androgen use outside of legitimate medical therapy is a perceived concern that is drawing attention across military and specifically Special Operations Forces (SOF) communities. For leadership and the medical community to properly address the issue and relate to those individuals who are using or considering use, it will be crucial to understand the scope of the problem. Limited data suggest that the prevalence of androgen use may be increasing, and inferences made from the scientific literature suggest that SOF may be a population of concern. While risks of androgen use are well known, there are little data specific to military performance that can be applied to a rigorous risk:benefit analysis, allowing myths and poorly supported theories to perpetuate within the community. Further efforts to define the potential benefits balanced against the short- and long-term risks should be undertaken. Providers within the SOF community should arm themselves with information to engage androgen users and leadership in meaningful discussion regarding androgen use.

Synthesis and antibacterial activity evaluation of two androgen derivatives

In this study two androgen derivatives were synthesized using several strategies; the first stage an aza-steroid derivative (3) was developed by the reaction of a testosterone derivative (1) with thiourea (2) in presence of hydrogen chloride. The second step, involves the synthesis of an amino-steroid derivative (4) by the reaction of 1 with 2 using boric acid as catalyst. The third stage was achieved by the preparation of an aminoaza-androgen derivative (6) by the reaction of 3 with ethylenediamine using boric acid as catalyst. In addition, the compound 6 was made reacting with dihydrotestosterone to form a new androgen derivative (7) in presence of boric acid. The following step was achieved by the reaction of 7 with chloroacetyl chloride to synthesize an azetidinone-androgen derivative (8) using triethylamine as catalyst. Additionally, a thiourea-androgen derivative (9) was synthetized by the reaction of 4 with dihydrotestosterone using boric acid as catalyst. Finally, the compound 9 was made reacting with chloroacetyl chloride in presence of triethylamine to synthesize a new azetidinone-androgen derivative (10).On the other hand, antibacterial activity of compounds synthesized was evaluated on Gram negative (Escherichia coli and Vibrio cholerae) and Gram positive (Staphylococos aureus) bacteria. The results indicate that only the compound 3 and 8 decrease the growth bacterial of E. coli and V. cholerae. Nevertheless, growth bacterial of S. aureus was not inhibited by these compounds. These data indicate that antibacterial activity exerted by the compounds 3 and 8 depend of their structure chemical in comparison with the controls and other androgen derivatives that are involved in this study

Androgen deprivation promotes intratumoral synthesis of dihydrotestosterone from androgen metabolites in prostate cancer

Intratumoral synthesis of dihydrotestosterone (DHT) from precursors cannot completely explain the castration resistance of prostate cancer. We showed that DHT was intratumorally synthesized from the inactive androgen metabolites 5α-androstane-3α/β,17β-diol (3α/β-diol) in prostate cancer cells via different pathways in a concentration-dependent manner. Additionally, long-term culture in androgen-deprived media increased transcriptomic expression of 17β-hydroxysteroid dehydrogenase type 6 (HSD17B6), a key enzyme of oxidative 3α-HSD that catalyzes the conversion of 3α-diol to DHT in prostate cancer cells. Correspondingly, the score for HSD17B6 in tissues of 42 prostate cancer patients undergoing androgen deprivation therapy (ADT) was about 2-fold higher than that in tissues of 100 untreated individuals. In men receiving ADT, patients showing biochemical progression had a higher HSD17B6 score than those without progression. These results suggested that 3α/β-diol also represent potential precursors of DHT, and the back conversion of DHT from androgen derivatives can be a promising target for combination hormone therapy.

Estrogen receptor β agonists affect growth and gene expression of human breast cancer cell lines

Expression of estrogen receptor β (ERβ) has been described to reduce growth of cancer cell lines derived from hormone-dependent tumors, like breast cancer. In this study we tested to what extent two ERβ agonists, androgen derivative 3β-Adiol and flavonoid Liquiritigenin, would affect growth and gene expression of different ERβ-positive human breast cancer cell lines. Under standard cell culture conditions, we observed 3β-Adiol to inhibit growth of MCF-7 cells in a dose-dependent manner, whereas growth of BT-474 and MCF-10A cells was suppressed by the maximum concentration (100nM) only. When treated in serum-free medium, all cell lines except of MDA-MB-231 were responsive to 1nM 3β-Adiol, and ZR75-1 cells exhibited a dose-dependent antiproliferative response. Providing putative mechanisms underlying the observed growth-inhibitory effect, expression of Ki-67 or cyclins A2 and B1 was downregulated after 3β-Adiol treatment in all responsive lines. In contrast, treatment with lower doses of Liquiritigenin did not affect growth. In MCF-7 cells, the highest dose of this flavonoid exerted proliferative effects accompanied by increased expression of cyclin B1, PR and PS2, indicating unspecific activation of ERα. In conclusion, the ERβ agonists tested exerted distinct concentration-dependent and cell line-specific effects on growth and gene expression. The observed inhibitory effects of 3β-Adiol on breast cancer cell growth encourage further studies on the potential of this and other ERβ agonists as targeted drugs for breast cancer therapy.

Long‐term prophylaxis of hereditary angioedema with androgen derivates: a critical appraisal and potential alternatives

Androgen derivatives are regarded as standard in the long-term prophylaxis of swelling attacks in patients with hereditary angioedema (HAE). Because of their relatively slow onset of action, they are not suitable for acute therapy. Long-term prophylaxis with androgen derivatives must be regarded critically, especially on account of their androgenic and anabolic effects, some of which are severe. The risk of adverse events increases with the daily dose and the duration of treatment. Thus, treatment always calls for close monitoring of patients with regard to potential adverse events. In addition, androgens are subject to numerous contraindications and they show interactions with a large number of other drugs. Off-label use, doping issues, clarification of reimbursement and the need to import the androgen derivatives, which are no longer marketed in Germany, result in additional effort for the treating physician in terms of logistics and time involved. In symptomatic treatment of acute attacks the intravenous substitution of C1-INH and - since 2008 - subcutaneous administration of icatibant are available. The two substances are well tolerated and their effect occurs rapidly and, when the diagnosis has been confirmed, reliably. In the light of these two treatment options for controlling acute attacks, prophylactic treatment of HAE patients with androgen derivatives such as danazol should be reassessed. Patients might benefit from a dose reduction or the withdrawal of androgen prophylaxis and attacks can be controlled with demand-oriented acute treatment using C1-INH or icatibant.

Hereditary angioedema: an update on available therapeutic options

There is no cure for hereditary angioedema (HAE). Therapeutic approaches consist of symptomatic therapy for acute attacks, short-term prophylaxis before surgery, and long-term prophylaxis for those with frequent and severe attacks. In Germany, C1-INH concentrate and icatibant are licensed for acute therapy. C1-INH concentrate, which is obtained from human plasma, is administered intravenously to restore the deficient C1-INH activity. This therapy, which has been available for decades, is effective and well-tolerated. Batch documentation is required by German law. The synthetic decapeptide icatibant is administered subcutaneously. It competes with bradykinin, the responsible inducer of edema formation, for binding to the bradykinin B2 receptor. Icatibant is also effective and well-tolerated, even on repeated administration. An additional human C1-inhibitor, a recombinant human C1-inhibitor and the recombinant inhibitor of kallikrein ecallantide are currently under development. There are no licensed treatment options available in Germany for long- and short-term prophylaxis. Androgen derivatives are established in long-term prophylaxis. However, they are associated with many adverse effects, some of which are severe. Many drug interactions also limit their use. They are contraindicated in pregnancy, lactation, for children and in cases of prostate cancer. Antifibrinolytics have fewer adverse effects but are also less effective than androgens. They are contraindicated in thromboembolic disease and impaired vision. If androgen therapy has too negative an effect on quality of life, it may be worth reducing the dose or discontinuing therapy entirely and treating attacks with acute therapy.

The androgen derivative 5α-androstane-3β,17β-diol inhibits tumor necrosis factor α and lipopolysaccharide induced inflammatory response in human endothelial cells and in mice aorta

BackgroundAn increasing body of evidence suggests that testosterone may exert beneficial effects against the development of atherosclerosis. These effects are thought to be the consequence of its conversion into estradiol and the activation of the estrogen receptors; however a direct role of androgens, such as dihydrotestosterone, has also been proposed. More recently, it has been shown that the transformation of the dihydrotestosterone to 5α-androstane-3α,17β-diol (3α-diol) and 5α-androstane-3β,17β-diol (3β-Adiol), generates two molecules unable to bind the androgen receptor, but with a high affinity for the estrogen receptors (ERs) in particular the β isoform. As the actions of testosterone may result from the balance between androgenic and estrogenic molecules originating from its catabolism, we investigated the effects of the 3β-Adiol on inflammatory responses in vitro in human endothelial cells and ex vivo in mice aortas. Methods and results3β-Adiol reverts the pro-inflammatory gene expression pattern induced by TNF-α in HUVECs as determined by a cDNA microrray approach. Q-real-time PCR and protein array approaches confirmed that TNF-α-induced ICAM-1, VCAM-1 and ELAM-1 as well as MCP-1 and IL-6 induction was affected upon 3β-Adiol pre-incubation. ICI 182780, an estrogen receptor antagonist and R,R-THC, an estrogen receptor β antagonist, counteracted the effect of 3β-Adiol while bicalutamide, an androgen receptor antagonist, had minor effects. 3β-Adiol exerted a similar action on macrophages. Finally in castrated male mice, 3β-Adiol significantly counteracted the LPS mediated mRNA induction of IL-6, ELAM-1and PECAM-1 in the aortas. Conclusion3β-Adiol reverts in vitro the TNF-α and LPS induced pro-inflammatory activation of endothelial cells and macrophages. 3β-Adiol in vivo modulates the inflammatory response induced by LPS in the arterial vascular wall.

Methyl 3β-methoxycarbonyloxy-4,4-dimethyl-17-oxo-16α-(3-oxobutyl)-16β-carboxylate

The title steroid, C29H44O7, is a new androgen derivative and a key inter­mediate for synthesizing novel anti-HIV steroid agents. There are four trans-fused rings in the structure. The three six-membered rings exhibit chair conformations, while the five-membered ring adopts an envelope conformation.

Synthesis and Structure Activity Relationship of Organometallic Steroidal Androgen Derivatives

We present here the synthesis and the structure activity relationship of a series of organometallic complexes of the steroidal androgens testosterone and dihydrotestosterone (DHT) substituted at the C-17 position of the steroid skeleton with an ethynyl substituent grafted with various sandwich or semisandwich organometallic units [ferrocenyl, (η5-C5H4)-Re(CO)3, (η5-C5H4)-Mn(CO)3, (η6-C6H5)-Cr(CO)3] and of 3β-androstanediol substituted at C-16 and C-17 respectively by a ferrocenyl vinyl and a ferrocenyl ethynyl unit. In contrast to the estradiol series, there are currently very few examples of organometallic steroidal androgens in the literature. The ethynyltestosterone derivatives were obtained via a Stille coupling reaction between the appropriate iodo-organometallics and 17β-ethynyltestosterone stannyl derivatives. The ethynyl-DHT derivatives were synthesized by addition of the corresponding acetylide to the C-17 carbonyl of the steroid. The crystal structures of two ferrocenyl and one rhenium complexes...

Effects of short-term and long-term danazol treatment on lipoproteins, coagulation, and progression of atherosclerosis: Two clinical trials in healthy volunteers and patients with hereditary angioedema

Background: Danazol is a synthetic androgen derivative frequently used as prophylaxis in patients with hereditary angioedema (HAE) due to complement-1 esterase inhibitor deficiency. However, danazol has been reported to decrease high-density lipoprotein cholesterol (HDL-C) levels and to adversely affect coagulation parameters, which are considered to be proatherothrombotic. Objective: The short- and long-term effects of danazol were evaluated on proatherogenic intermediate end points in healthy volunteers and patients with HAE. Methods: Short-term effects were evaluated in healthy men randomly assigned to 200 mg/d of danazol or placebo for 4 weeks in a crossover trial with no washout period. Long-term effects of danazol on lipoproteins, coagulation, and carotid intima-media thickness (CIMT) were evaluated in a cross-sectional study in which patients with HAE treated with danazol, a mean dose of 170 mg/d for ≥2 years, were compared with healthy controls matched for age, sex, and body mass index (BMI). Drug tolerability was assessed by questionnaires and adherence was measured by pill count whendrug bottles were returned after every study visit. Results: Patients in the short-term study were 15 men with a mean (SD) age of 32.6 (6.9) years and BMI of 24.3 (4.1) kg/m 2. In the long-term study, patients with HAE were 10 women and 7 men with a mean (SD) age of 41.1 (12.9) years and BMI of 25.4 (2.6) kg/m 2; the 17 matched controls had a mean (SD) age of 39.8 (11.8) years and BMI of 25.4 (2.6) kg/m 2. Short-term danazol treatment was associated with a decrease from baseline in apolipoprotein A-I of 21% and in HDL-C of 23%. Flow-mediated dilation and coagulation parameters were unaffected after 4 weeks. Longterm danazol treatment did not adversely affect HDL-C concentration (1.1 [0.5] vs baseline, 1.2 [0.5] pmol/L), HDL-related transfer proteins such as paraoxonase-1 activity (92 [62] vs 80 [40] U/mM), cholesteryl-ester transfer protein mass (1.5 [0.4] vs 2.2 [0.6] µg/mL), lecithin cholesterol acyltransferase activity (21.2 [4.5] vs 32.1 [7.2] nmol CE · mL -1 · h -1), plasma phospholipid transfer protein activity (15.4 [1.5] vs 14.9 [1.2] AU), and apolipoproteins between patients with HAE and controls. The mean (SD) CIMT was similar between patients with HAE and controls (0.62 [0.09] vs 0.59 [0.08] mm; P = NS). However, HAE patients using danazol had increased coagulation activation when compared with controls (prothrombin fragments, 286 [119] vs 164 [57] pmol/L, P = 0.002; thrombinantithrombin complex, 3.9 [1.4] vs 2.6 [1.1] µg/L, P = 0.01). Conclusions: Short-term danazol treatment in healthy volunteers was associated with a reduction in HDL-C levels without a significant effect on endothelial function or coagulation parameters. In contrast, patients with HAE treated for >2 years with danazol had increased activation of coagulation, but there were no significant differences in HDL-C or CIMT compared with matched healthy controls.

Clinical outcome of vaginal danazol suppository use in women with pelvic endometriosis

OBJECTIVE: Danazol (DZ), a weak androgen derivative, is a drug used for conservative treatment for endometriosis. DZ has been administered orally, and has often induced some adverse effect such as liver dysfunction, acne and increase in body weight. To exert its direct effect on pelvic endometriosis and to minimize these side effects, we have utilized vaginal DZ suppository since 1991. In our preliminary study, in which DZ concentration in pelvic organs were measured after vaginal DZ suppository use, we have shown that concentrations in the peritoneal fluid and the pelvic organs after vaginal administration were equal to those after oral administration, whereas the serum concentration was almost undetectable in the vaginal group.

Preclinical studies of MDX-12C, a selective membrane androgen receptor ligand with activity in prostate cancer

14549 Background: Membrane Androgen Receptor (mAR) is a novel, yet unknown GPCR functionally distinct from the classical intracellular Androgen Receptor (iAR). mAR is frequently over-expressed in aggressive prostate cancer and initiates rapid non-genomic signaling resulting to tumor cell death by apoptosis in both iAR-positive and iAR-negative cell lines. Methods: MDX-12C is a novel mAR binding ligand comprising a male androgen derivative conjugated to Human Serum albumin (HSA). MDX-12C was evaluated for its potency in vitro against various androgen dependent (LNCaP) and independent (PC-3, DU145) cell lines and in DU145-derived mouse xenografts co-treated with paclitaxel. Fluorescent MDX-12C derivatives were used to assess mAR expression in prostate, breast and colon tumor tissue. Finally, mAR-dependent signaling events and pathways activated by MDX-12C treatment were analyzed. Results: MDX-12C induced potent apoptotic regression of prostate cancer cell lines in vitro. This effect was independent of iAR expression or co-treatment with iAR antagonists. MDX-12C activates two distinct pathways resulting in actin cytoskeleton re-organization and apoptosis: (I) a FAK/PI-3/Rac/cdc-42 pathway in iAR+ cell lines and (II) a RhoA/ROCK/LimK2 pathway in iAR- cell lines. In both cases, apoptotic cell death was marked by caspase-3 activation and FasL over-expression. In vivo, MDX-12C synergizes with paclitaxel resulting in significant tumor growth delay and prolongation of overall survival. Finally, analysis of mAR expression in xenograft tissue isolated from tumor-bearing mice indicated strong mAR expression not only in prostate, but also in breast and colon tissue. Conclusions: The findings support development of MDX-12C as a molecular targeted therapy in mAR-positive prostate tumors independently of their iAR status. Further development for breast and colon cancer is also indicated. No significant financial relationships to disclose.

Nutritional Effect of Nandrolone Decanoate in Predialysis Patients With Chronic Kidney Disease

The study objective was to examine the nutritional effect of nandrolone decanoate, an androgen derivative, in predialysis patients with chronic kidney disease (CKD). This was a prospective and experimental study. The study was performed at the institutional level of clinical care. Twenty-nine predialysis patients with CKD, with a glomerular filtration rate between 5 and 30 mL/min and moderate to severe malnutrition, were included and randomly divided into control (n = 13) and nandrolone decanoate (NAN, n = 16) groups. Patients in the control group received optimally conventional treatment of CKD. Patients in the NAN group, in addition to the conventional treatment, were intramuscularly injected with nandrolone decanoate at the dose of 100 mg per for 3 months. Nutritional markers, including lean body mass (LBM), normalized protein catabolic rate, serum albumin, and lipids, were determined at baseline and 3-month periods. Baseline parameters in both groups were not different. After 3 months, the patients in the NAN group had increased LBM (P < .01) and decreased serum albumin levels (P < .05), but no changes in the values of normalized protein catabolic rate, serum lipids, hematocrit, and glomerular filtration rate. No alterations in all parameters were identified in the control group. Changes in LBM in the NAN group were significantly higher than in the control group (P < .05). Minor adverse effects were observed in a few patients in the NAN group. Nandrolone decanoate expresses an anabolic effect on LBM without altering the renal function and thus would provide nutritional benefit in predialysis patients with CKD.

Development of a high-performance reporter plasmid for detection of chemicals with androgenic activity.

A number of chemicals are present in the environment, and some synthetic chemicals may disrupt endocrine function of wild animals and humans. An effective procedure to screen chemicals for endocrine modulating activity has been needed to ensure the safety of chemicals, and the reporter gene assay technique may provide a powerful tool for screening endocrine-disrupting chemicals. We have developed a high-performance reporter plasmid that can trigger high androgen-dependent induction with high selectivity by using mouse mammary tumor virus (MMTV) androgen-responsive elements and a partial fragment of the rat alpha(2u)-globulin promoter region. This new type plasmid can induce higher transcriptional activation than a commercial PGV-P-based construct bearing the SV40 promoter fragment, and the basal induction level of this plasmid is much lower than that of the PGV-P-based construct. Moreover, only androgen derivatives could selectively induce a high response in the reporter gene assay with the new reporter plasmid. This new type of reporter plasmid, ARE-AUG- Luc+, should be of value in endocrine research and in screening to identify endocrine-modulating chemicals.

Immature rat uterotrophic assay of 18 chemicals and Hershberger assay of 30 chemicals

We performed an immature rat uterotrophic assay of 18 chemicals and Hershberger assay of 30 chemicals to assess the relationship between the results of two assays. The chemicals tested by the uterotopic assay were 4-n-amylphenol, p-dodecyl-phenol, p-(tert-pentyl)phenol, 4-cyclohexylphenol, 4-(1-adamantyl)phenol, 4,4′-thiobis-phenol, diphenyl-p-phenylenediamine, 4-hydroxyazobenzene, 4-(phenylmethyl)phenol, 4,4′-(hexafluoroisopropylidene)diphenol, 2,2-bis(4-hydroxyphenyl)-4-methyl-n-pentane, 4,4′-(octahydro-4,7-methano-5H-inden-5-ylidene)bisphenol, 4,4′-dihydroxybenzophenone, 2,2′,4,4′-tetrahydroxybenzophenone, 4-hydroxybenzophenone, 2,4,4′-trihydroxybenzophenone, testosterone enanthate, and methyltestosterone. The chemicals tested by the Hershberger assay were the 18 chemicals tested in the uterotrophic assay plus the following: 17alpha estradiol, estrone, equilin, norethindrone, norgestrel, ethynyl estradiol, bisphenol A, bisphenol B, bisphenol F, 4-tert-octylphenol, p-cumyl phenol, and nonylphenol. All chemicals examined in this study were positive in a reporter gene assay for ER-alpha. In the immature rat uterotrophic assay, all chemicals induced uterotrophy and p-(tert-pentyl)phenol, 4,4′-thiobis-phenol, 4-(phenylmethyl)phenol, 4,4′-(hexafluoroisopropylidene)diphenol, 2,2-bis(4-hydroxyphenyl)-4-methyl-n-pentane, 4,4′-(octahydro-4,7-methano-5H-inden-5-ylidene)bisphenol, 4,4′-dihydroxybenzophenone, 2,2′,4,4′-tetrahydroxybenzophenone, 4-hydroxybenzophenone, and 2,4,4′-trihydroxybenzophenone exerted both estrogen agonistic effect and reduced the estrogenic effect of ethynylestradiol. In the Hershberger assay, a clear androgen agonistic effect was detected in the androgen derivatives testosterone enanthate and methyltestosterone.

Steroid Levels and Steroid Metabolism in Relation to Early Gonadal Development in the TilapiaOreochromis niloticus(Teleostei: Cyprinoidei)

Sex steroid levels and steroid metabolism were investigated in relation to early gonadal development in a mixed sex population of the tilapiaOreochromis niloticus.Androstenedione (AD), testosterone (T), 11-ketotestosterone (KT), and estradiol (E2) were quantified by radioimmunoassay (RIA) of whole body extracts. Androstenedione metabolism was assessed by incubationsin vitrowith3H-AD and metabolites were identified by thin-layer chromatography coupled with radioisotope image analysis. Histology revealed the presence of gonadal structures at 15 days postfertilization (dpf) and ovaries at 36 dpf, with other individuals exhibiting undifferentiated gonads containing germinal cells, presumably eventual testes. Androgen levels were initially high in eggs then decreased severalfold prior to the emergence of gonads. A transient increase in the levels of T and KT occurred at 22 dpf. Levels of E2 were either low or undetectable except for a transient increase (43 dpf) after ovaries were present. Levels of T approached bimodality from 57 to 64 dpf. Steroid metabolism generally increased throughout development. Metabolites were generally similar, consisting of T predominantly as well as 5β-reduced androgen derivatives and 11-oyxgenated derivatives. Estriol was tentatively identified. Conjugated steroids were not formed. Two types of steroid metabolic profiles occurred at 50 dpf. These results demonstrate that changes in the steroidogenic profile occur during early transitions of gonadal development. Notably, (1) steroid biosynthetic capacity preceeds gonadal differentiation, (2) evidence for estrogens occurs after ovarian development has begun, and (3) bimodality of levels of T and differential steroid metabolism later in development may reflect the onset of sexual divergence.

Metabolic androgenization of female Daphnia magna by the xenoestrogen 4‐nonylphenol

AbstractVrtebrates and invertebrates metabolize testosterone to a variety of less‐polar derivatives that elicit varying degrees of androgenicity as well as polar elimination products. We have developed a model, using the cladoceran Daphnia magna, with which the ability of xenobiotics to alter steroid hormone metabolism can be assessed and possible physiologic consequences evaluated during a 3‐week assay. This model was used to assess the effects of the xenoestrogen 4‐nonylphenol on steroid‐metabolic processes. Exposure of daphnids to 100 μg/L 4‐nonylphenol for 48 h caused a significant increase in the accumulation of radioactivity derived from [14C]testosterone provided to the exposure media. More definitive analyses demonstrated that both 25 and 100 μg/L 4‐nonylphenol disrupted components of the testosterone metabolic pathway that would lead to a decrease in the metabolic elimination of testosterone and an increase in the accumulation of androgenic derivatives. Exposure of daphnids to 100 μg/L 4‐nonylphenol significantly decreased fecundity of the organisms while having no effect on survival of the parental organisms. Comparison of metabolic and reproductive effects of 4‐nonylphenol revealed that 71 μg/L, the reproductive chronic value, would reduce the metabolic elimination of testosterone by approximately 50%. This relationship is consistent with that which we have reported for other toxicants and identifies a mechanism, in addition to estrogenicity, that may contribute to the reproductive toxicity of this compound.

Osteoblast cells (MG-63 and HOS) have aromatase and 5 alpha-reductase activities.

Both aromatase and 5 alpha-reductase activities were found by whole-cell assay in osteoblast-like cells, MG-63 and HOS. Aromatase activity was measured by the [3H] water release method, and the formation of 5 alpha-androstanedione from androstenedione was expressed as 5 alpha-reductase activity. When CGS16949A, an inhibitor of aromatase, was added to the incubation medium at a concentration of 2 x 10(-9) M, sufficient to completely inhibit placental aromatase activity, only 63% to 68% inhibitions were observed. When progesterone, a competitive inhibitor of 5 alpha-reductase, was added at a concentration of 10(-5) M, 28% to 40% inhibitions were recorded. Because the release of [3H] from [1 beta-3H] androstenedione into water by 5 alpha-reductase is reported, results from the present study suggest that the measurement of aromatase activity in osteoblasts by the [2H] water release method may overestimate aromatase activity owing to the inclusion of 5 alpha-reductase activity. The results also suggest that osteoblast cells may play an important role in bone metabolism by transforming androgens into estrogens and more biologically active androgen derivatives.

Plasma protein changes induced by two orally administered androgen derivatives

Epostane is a synthetic 17 alpha-alkylated 5 beta-androstane derivative, active following oral administration and devoid of any apparent androgenic, estrogenic or antiestrogenic potency. Circulating concentrations of 13 different plasma proteins were measured in eight women before and after 2 and 4 weeks of daily oral intake of 600 mg of epostane. The results were compared with those previously found during administration of the same daily dose of danazol, a synthetic 17 alpha-alkylated androgen derivative with known androgenic/anabolic activity. Epostane significantly suppressed serum levels of sex hormone-binding globulin, pregnancy zone protein and thyroxin-binding globulin and increased the levels of transthyretin. Haptoglobins, plasminogen and transferrin showed minor and/or transient changes and the levels of high density lipoproteins, alpha2-macroglobulin, albumin, C1-esterase inactivator, C3 complement and transcortin remained unaffected. The pattern of changes in plasma proteins was almost identical to that induced by administration of danazol, although the effects of epostane were somewhat weaker. Thus epostane is capable of inducing substantial changes in the pattern of steroid-sensitive plasma proteins in an androgen-like fashion despite its apparent lack of androgenic activity. The capacity of a steroid to induce such changes thus seems to be tied to the chemical structure rather than to the intrinsic hormonal activity of the molecule.

Activation of the contact system and fibrinolysis in autoimmune acquired angioedema: A rationale for prophylactic use of tranexamic acid

Cl-inhibitor deficiency results in bouts of mucocutaneous edema and may be inherited (hereditary angioedema) or acquired (acquired angioedema [AAE]). The two forms have the same clinical picture but differ in the response to treatment. Prophylaxis with antifibrinolytic agents produces better results in the acquired form than in the inherited form, in which androgen derivatives are more effective. It is hypothesized that activation of the contact and fibrinolytic systems is involved in the pathogenesis of attacks. We evaluated these two systems in plasma from eight patients with AAE and anti-Cl-inhibitor autoantibodies (autoimmune AAE) by measuring the cleavage of high molecular weight kininogen and the complexes formed by plasmin and its inhibitor α 2-antiplasmin. We also measured complement parameters, autoantibody titer, and cleaved Cl-inhibitor (relative molecular mass = 96,000), because autoantibodies to Cl-inhibitor are known to facilitate its cleavage by proteases. Plasma was obtained from patients in remission, during prophylactic treatment with the antifibrinolytic agent tranexamic acid (2 to 4.5 gm/day) and also from two patients during acute attacks of edema. Levels of cleaved high molecular weight kininogen and antiplasmin-plasmin complexes in patients with AAE were both higher in basal conditions, during treatment, and during acute attacks than those in normal subjects ( p < 0.001). The cleaved inactive form of Cl-inhibitor was also present in all patients in all three conditions. Therapy with antifibrinolytic agents reduced the frequency and intensity of symptoms without significantly changing any of the biochemical parameters. Our data demonstrate that in patients with autoimmune AAE there is continuous activation of contact and fibrinolytic systems, which might be counteracted by antifibrinolytic agents, as indicated by the favorable effects of prophylactic treatment with tranexamic acid.