The prohormone 19-norandrostenedione displays selective androgen receptor modulator (SARM) like properties after subcutaneous administration.

One of the most frequently misused steroid precursors (prohormones) is 19-norandrostenedione (4-estrene-3,17-dione, NOR), which is, after oral administration, readily metabolised to nortestosterone, also known as nandrolone (durabolin). In this study we have characterised molecular mechanisms of its action determined its tissue specific androgenic and anabolic potency after subcutaneous (s.c.) administration and investigated potential adverse effects. Receptor binding tests demonstrate that NOR binds with high selectivity to the AR. The potency of NOR to transactivate androgen receptor (AR) dependent reporter gene expression was 10 times lower as compared to dihydrotestosterone (DHT). In vivo experiments in orchiectomised rats demonstrated that s.c. treatment with NOR resulted only in a stimulation of the weight of the levator ani muscle; the prostate and seminal vesicle weights remained completely unaffected. Like testosterone, administration of NOR resulted in a stimulation of AR and myostatin mRNA expression in the gastrocnemius muscle. NOR does not affect prostate proliferation, the liver weight and the expression of the tyrosine aminotransferase gene (TAT) in the liver. Summarizing these data it is obvious that NOR, if administrated s.c. and in contrast to its metabolite nandrolone, highly selectively stimulates the growth of the skeletal muscle but has only weak androgenic properties. This observation may have relevance with respect to therapeutic aspects but also doping prevention.

Characterisation of the pharmacological profile of desoxymethyltestosterone (Madol), a steroid misused for doping.

Desoxymethyltestosterone (DMT), also known as Madol, is a steroid recently identified to be misused as a doping agent. Since, the knowledge of functions of this substance is rather limited, it was our aim to characterise the pharmacological profile of DMT and to identify potential adverse side effects. DMT was synthesised, its purity was confirmed and its biological activity was tested. The potency of Madol (DMT) to transactivate androgen receptor (AR) dependent reporter gene expression was two times lower as compared to dihydrotestosterone (DHT). Receptor binding tests demonstrate that DMT binds with high selectivity to the AR, binding to the progesterone receptor (PR) was low. In vivo experiments in orchiectomised rats demonstrated that treatment with DMT resulted only in a stimulation of the weight of the levator ani muscle; the prostate and seminal vesicle weights remained unaffected. Like testosterone, administration of DMT resulted in a stimulation of IGF-1 and myostatin mRNA expression in the gastrocnemius muscle. In the prostate proliferation was stimulated by TP (testosteronepropionate), but remained unaffected by DMT. Remarkably, treatment with DMT, in contrast to TP, resulted in a significant increase of the heart weight. In the liver, DMT slightly stimulates the expression of the tyrosine aminotransferase gene (TAT). Our results demonstrate that DMT is a potent AR agonist with an anabolic activity. Besides the levator ani weight, DMT also modulates the gene expression in the musculus gastrocnemius. The observed stimulation of TAT expression in the liver and the significant increase of the heart weight after DMT treatment can be taken as an indication for side effects. Summarizing these data it is obvious that DMT is a powerful anabolic steroid with selective androgen receptor modulators (SARM) like properties and some indications for toxic side effects. Therefore, there is a need for a strict control of a possible misuse.

Tetrahydrogestrinone is a potent but unselective binding steroid and affects glucocorticoid signalling in the liver.

Tetrahydrogestrinone (THG) is a steroid recently identified to be misused as doping agent. However, the knowledge on functions of this substance in humans or animal models is rather limited. Therefore, it was our aim to further characterize the pharmacological profile of THG and identify potential adverse side effects. THG was synthesized, the purity was confirmed and its biological activity was tested. The potency of THG to transactivate AR dependent reporter gene expression was two orders of magnitude lower compared to dihydrotestosterone. THG binds with high affinity but unselective to the androgen (AR), progesterone (PR), glucocorticoid (GR) and mineralocorticoid (MR) receptor. Treatment of orchiectomised rats with THG resulted in a stimulation of prostate, seminal vesicle and levator ani muscle, indicating androgenic and anabolic properties. In the liver THG, in contrast to testosteronepropionate (TP), down regulates the expression of the GR dependent tyrosine aminotransferase gene (TAT). In summary, our results demonstrate that THG is not a specific AR agonist. THG exhibits a high binding affinity to all tested steroid hormone receptors and binds with highest affinity to the GR. Our in vivo data are indicative of an anabolic and androgenic potency of THG, but the repression of TAT demonstrates that THG also interferes with the glucocorticoid hormone system. Therefore, it is conceivable that an intake will result in adverse side effects.

17beta-hydroxy-5alpha-androst-1-en-3-one (1-testosterone) is a potent androgen with anabolic properties.

Since the begining of the year 2005, the use of steroid precursors (prohormones) is illegal in the United States; nevertheless, there is still an enormous abuse of such substances. One of the most frequently misused steroids, often declared to be a prohormone, is 1-testosterone (17beta-hydroxy-5alpha-androst-1-en-3-one, 1-Testo). In this study, we have characterised molecular mechanisms of its action, determined its tissue specific androgenic and anabolic potency and investigated potential adverse effects. 1-Testo binds highly selective to the androgen receptor (AR) and has a high potency to stimulate AR dependent transactivation. In vivo an equimolar dose of 1-Testo has the same potency to stimulate the growth of the prostate, the seminal vesicles and the androgen sensitive levator ani muscle as the reference compound testosterone propionate (TP). Administration of 1-Testo, in contrast to TP, results in a significant increase of liver weight. Our results demonstrate that 1-Testo, even without being metabolised, is a very potent androgen. It binds selectively to the AR and transactivates AR dependent reporter genes. In vivo it has a high androgenic and anabolic potency and increases liver weight. In summary 1-Testo can be characterised as a typical anabolic steroid. It has to be assumed that consumption of this substance is associated with adverse side effects typical for this class of compounds. Therefore, a strict control of its ban is essential.

Tissue-specific modulation of cyclooxygenase-2 (Cox-2) expression in the uterus and the v. cava by estrogens and phytoestrogens.

Cyclooxygenase 2 (Cox-2), an enzyme involved in prostaglandin production, is a key player in the development of pathologic changes, such as colorectal cancer, arteriosclerosis and thrombosis. In this study, we investigated the effects of estrogens, selective estrogen receptor modulators (SERMs), pure antiestrogens and phytoestrogens on the tissue-specific expression of Cox-2 in the uterus and the v. cava of ovariectomized female rats. Cox-2 expression could be detected in the uterine epithelium and in the endothelium of the v. cava. Cox-2 expression was time-dependently stimulated after administration of 17beta estradiol (E2) in the uterus. In the v. cava, E2 treatment resulted in a stimulated expression of the progesterone receptor (PR), a gene known to be regulated by E2, whereas Cox-2 was simultaneously down-regulated. Administration of the pure antiestrogen faslodex (Fas) had no effect on Cox-2 expression. In contrast, administration of tamoxifen (Tam) resulted in a decrease of Cox-2 expression in the v. cava but does not stimulate Cox-2 expression in the uterus. Interestingly, the same expression pattern of Cox-2 could be detected after dose-dependent administration of genistein (Gen). Here, down-regulation of Cox-2 could already be detected after administration of merely 0.5 mg/(kgBW) Gen, a dose where no effects on uterine weight were observed. In summary, our results demonstrate a reverse tissue-specific regulation of Cox-2 expression by estrogens in the v. cava and uterus indicating the existence of complex molecular mechanisms which have to be characterized in future studies. Remarkably, Tam and the phytoestrogen Gen, both share the ability to decrease the expression of Cox-2 in the v. cava without effecting its uterine expression. These observations may be of great importance with respect to potential beneficial or adverse effects of estrogens, SERMs and phytoestrogens on the cardiovascular tissue.

Anabolic and androgenic activity of 19-norandrostenedione after oral and subcutaneous administration--analysis of side effects and metabolism.

One of the most frequently misused steroid precursors (prohormones) is 19-norandrostenedione (estr-4-ene-3,17-dione, NOR). Recently we have show that NOR stimulates skeletal muscle growth after s.c. administration in a highly selective manner but exhibits only weak androgenic activity in rats. Because most abusers take NOR orally, the aim of this study was to compare the anabolic and androgenic potency of NOR between s.c. and oral application. Orchiectomised rats were treated with NOR either s.c. (1 mg/kg BW/day) or orally (0.1, 1 and 10 mg/kg BW/day). The tissue weights of the levator ani, the seminal vesicle and the prostate were analysed to determine the anabolic and androgenic activity. Heart and liver wet weights were examined to identify side effects. Serum concentrations of NOR and its metabolite nandrolone (NT) were determined. GCMC analysis revealed that free and glucuronidated NOR and NT were detectable in the serum after oral and s.c. administration and that NOR was converted to NT in comparable amounts independent of the route of administration. In agreement to our previous study s.c. application of NOR stimulates skeletal muscle growth but has only weak androgenic effects. In contrast, after oral administration of NOR neither stimulation of the prostate nor the levator ani could be observed in the doses administered in this study. Interestingly, and in contrast to s.c. treatment, oral administration of NOR resulted in a dose-dependent decrease of body weight. In summary, oral administration of NOR, at least in the rat, seems to be a very ineffective strategy for stimulating skeletal muscle mass increases but may be associated with side effects.