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The Effects of Pharmaceuticals, Environmental, and Occupational Agents on Sperm Motility
Published in Claude Gagnon, Controls of Sperm Motility, 2020
Changes in semen quality induced by cyproterone can be counteracted by the administration of an androgen such as mesterolone.66 This is in accordance with the principal mode of antiandrogen action, which is a competition with testosterone and dihydrotestosterone for androgen receptors. If the target organ is the seminiferous tubules and, specifically, the Sertoli cells, then the antiandrogens, including cyproterone acetate, are able to block the access of androgen to Sertoli cells thereby preventing the formation of the androgen-binding protein, which is essential for intriftesticular androgen transport.
Gonadotropins and Sex Hormones
Published in Istvan Berczi, Pituitary Function and Immunity, 2019
Rat thymuses were shown to contain steroidal 5α -reductase, which can convert testosterone to androgenic metabolites.172 Treatment of X-irradiated (400 R) rats with testosterone or mesterolone accelerated the recovery of leukocytes.173 Testosterone administration to normal male and female rats caused an increased erythropoiesis and granulopoiesis. At the same time the bone marrow and thymus lymphocytic cellularity was diminished. Peripheral lymphoid tissue was not affected. Humoral immune responsiveness was increased and normal inflammatory response was retained.174
Stimulation of Endogenous Fibrinolysis
Published in Cornelis Kluft, Tissue-Type Plasminogen Activator (t-PA): Physiological and Clinical Aspects, 1988
Gordon D. O. Lowe, Michael Small
The fibrinolytic enhancing effect of stanozolol and ethylestrenol appears to depend on their 17 α-alkyl group. Other 17 α-alkyl steroids which stimulate fibrinolysis, at least in the short term, include norethandrolone, methandienone, methylandrostenediol, and oxy-metholone;196,197 similar effects were recently observed with danazol198,199 and Org OD14.200 In contrast, the non-17 α-alkyl steroids, methenolone acetate197 and mesterolone,201 did not enhance fibrinolysis in the short term. Interestingly, administration of the latter drug for its androgenic effects to otherwise healthy young men has been associated with spontaneous deep vein thrombosis in a small number of cases,201 although no short-term prothrombotic changes were seen in a volunteer study.201
Anabolic-androgenic steroids: procurement and administration practices of doping athletes
Published in The Physician and Sportsmedicine, 2019
Julius Fink, Brad Jon Schoenfeld, Anthony C. Hackney, Masahito Matsumoto, Takahiro Maekawa, Koichi Nakazato, Shigeo Horie
According to a survey by Weber et al., testosterone, especially the enanthate ester, seems to be the most popular drug on the black market, followed by methandienone, stanozol, nandrolone, oxandrolone, boldenone, mesterolone, trenbolone, oxymetholone and methenolone [9]. Another survey showed similar prevalence for certain AAS on the black market: Testosterone (78.2%), methandienone (64.9%), nandrolone decanoate (63.5%), stanozolol (56%), boldenone undecanoate (53.9%), Trenbolone (51.3%), oxymetholone (37.7%), oxandrolone (37%), methenolone (28.2%), methyltestosterone (26.1%), drostanolone (20%) and fluoxymesterone (19.4%) [3]. In addition to AAS approved for human use, several unapproved forms of AAS intended for animal use are popular amongst athletes (Table 1). From the data of a recent study investigating the Google search trends with regard to AAS, seasonal fluctuations for several AAS have been observed [11]. For instance, ‘hardening’ agents (i.e. AAS thought to decrease body fat while increasing muscle mass without water retention) used by bodybuilders pre-contest such as oxandrolone, trenbolone and stanazolol show peaks during pre-contest/contest season (spring/summer), whereas compounds used year-round such as testosterone do not show such seasonal trends [11].
Pharmacological management of late-onset hypogonadism
Published in Expert Review of Clinical Pharmacology, 2018
Giulia Rastrelli, Mario Maggi, Giovanni Corona
Mesterolone (1α-methyl-4,5α-dihydrotestosterone) is a derivative of 5α-dihydrotestosterone (DHT), the most active ligand for the androgen receptor. The methyl group in 1α position enhances its resistance to hepatic metabolism. Similar to DHT, mesterolone cannot be converted to estrogen through the activity of P-450 aromatase, hence it does not share the full spectrum of biological actions of native T. Accordingly, mesterolone relatively maintains Gns and this can represent an advantage in some contexts, such as fertility preservation. However, the lack of a full spectrum of T bioactivity––and in particular on bone metabolism––strongly limits its attractiveness. Mesterolone is prescribed at a daily dose of 50–100 mg and should be taken in two to three evenly spaced dosages [1–3,5].