Biological effects of androgens

The biological effects of androgens on target organs of male animals... 

The first chapter deals with metabolic factors affecting the biological activities of androgens. In the second chapter the structure-activity theories are reviewed. A new approach to the structure-activity relationship is offered in Chapter 3. The effects of structural and stereochemical changes on biological activities are extensively analyzed in this chapter. A new theory of steroid-receptor interaction concludes this chapter. 

The effect of 1-alkyl substitution in decreasing the androgenicity of a number of 5a-androstanes has been noted and a proposal regarding the structural requirements for biological activity of androgens has been made. ... 

Armas OA, Aprikian AG, Melamed J, et al. Clinical and patho-biological effects of neoadjuvant total androgen ablation therapy on clinically localized prostatic adenocarcinoma. Am J Surg Pathol. 1994 18 979. 

The biological effects of testosterone can be considered by the receptor it activates and by the tissues in which its effects occur at various stages of life. Testosterone can act as an androgen either directly, by binding to the AR, or indirectly by conversion to dihydrotestosterone, Testosterone also can converted to estradiol, which activates the estrogen receptor (Figure 58 ). 

The androgens and oestrogens represent the major male and female sex hormones respectively (Figure 11.B3). The testicular Leydig cells represent the primary source of androgens in the male, of which testosterone is the major one. Testosterone, in turn, serves as a precursor for two additional steroids, i.e. dihydrotestosterone and the oestrogen called oestradiol. These mediate many of its biological effects. 

Due to the unique biological similarity of drospirenone (e.g., mild anti-aldosterone and anti-androgenic activity) to the natural progesterone, Yasmin has important advantages over the known oral contraceptives [14]. For example, the use of Yasmin does not initially cause any increase in body weight, and it is also effective in treating mild to moderate acne. Likewise, menstrual cycle control is excellent. 

Excellent accounts of the biological effects and clinical application of anabolic steroids, by Kriiskemper [5], and of the pharmacology of anabolic steroids, by Overbeek [50], are available. It is the aim of this book to examine the chemical structure-biological activity relationship of androgens and anabolic agents. A new theory of steroid-receptor interaction is also advanced, based on a new approach to the chemical structure-biological activity relationship. 

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