Androgen naturally occurring

Classification of the anabolic steroids is based on chemical stmctures and associated actions. A review of the biosynthesis and metabolism of the naturally occurring estrogens and androgens is available (1). Names, descriptions, approval dates, and recommended doses of the commercial products are found in References 1, 8, and 9. Although steroids may be orally active, the FDA approved mode of adrninistration is the subcutaneous implant. Effective dose is lower with implant rather than oral adrninistration. 

Androgens act via the AR and play an important role in the development and differentiation of the male sexual organ. Furthermore, they are involved in several diseases, the most important being partial and complete androgen insensitivity syndrome (AIS formerly known as the testicular feminization syndrome), spinal and bulbar muscle atrophy (SBMA Kennedy s disease), and the neoplastic transformation of the prostate. The two natural occurring androgens are testosterone (T) and the... 

Boldenone (17 -boldenone) is an androgenic steroid with known anabolic properties. As the oxidation of 17-ol to 17-one steroids is a recurring pathway both in vivo and in vitro, boldenone studies in cattle liver microsomes performed in vitro showed that the most prominent metabolite formed was androst-l,4-diene-3,17-dione 111). Not long ago, it was assumed drat the presence of boldenone or its main metabolite in the urine implied illegal administration of this steroid to the animal. Evidence has been recently presented that the presence of only the boldenone metabolite in urine cannot be taken as a proof of the illegal use of tills compound because boldenone is a naturally occurring steroid in urine of cattle (12). Nevertheless, the presence of 17 -boldenone in urine at levels above... 

Naturally occurring and synthetic estrogens and androgens have been extensively and safely used to improve efficiency and carcass composition in growing beef catde in the United States since the eady 1950s. Several anabolic steroid implants have been approved for use in beef catde in the United States, but only one, zeranol [55331 -29-8] > is approved for use in lambs. Anabolic steroids are not used for growth regulation in swine or poultry (see STEROIDS). 

Disposition in the Body. Androsterone is a naturally occurring androgen which may be isolated from male urine. It is a major metabolite of testosterone. 

Evaporative dysfunction is caused by a reduction in the lipid layer of the tear film. Most often, this condition is caused by MGD or blepharitis. MGD is traditionally conceptualized as a triad of meibomianitis (stagnated secretions within the meibomian glands), meibomian seborrhea (overabundance of meibomian secretions into the tear film), and seborrheic blepharitis (oily debris visible on the eyelashes and ocular adnexal surfeces). Additionally, we have become increasingly aware of the influence of male hormones, or androgens, on the health of the meibomian glands. Clinically significant androgen deficiency, which naturally occurs in women of menopausal age and men in... 

Anabolic steroids promote muscle development and, therefore, potentially enhance performance. Their use is forbidden or monitored closely in most countries. Sophisticated methodologies exist to detect these substances and their metabolites and to discriminate them from naturally occurring androgenic hormones in the blood and urine. Anabolic steroids may be employed as adjunctive therapy in horses with debilitating conditions or chronic liver disease, anemia and postsurgical... 

As shown in Figure 5.3, pregnenolone (I) is oxidised to progesterone (II) and thence converted via 17a-hydroxyprogesterone (III) into testosterone (V). Testosterone is the most active of the naturally occurring androgens [9, 10]. Androstenedione (VI) and dehydroepiandrosterone (DHA) (IV) form less potent but quantitatively more significant secretion products. 

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