INDEX androgens

Kapoor P, LuttreU BM, Williams D. The free androgen index is not valid for adult males. J Steroid Biochem Mol Biol 1993 45 325-6. 

Wilke TJ, Utley DJ. Total testosterone, free-androgen index, calculated free testosterone, and free testosterone by analog RIA compared in hirsute women and in otherwise-normal women with altered binding of sex-hormone-binding globulin. Chn Chem 1987 33 1372-5. 

Testosterone and SHBG concentrations arc sometimes reported by the laboratory as a ratio (the free androgen index) which gives a clearer indication of androgen status than does serum testosterone alone. 

The most important function of the 4,5-double bond seems to be the protection of the 3-carbonyl function against metabolic inactivation. It is known that 5a-dihydrotestosterone is a more powerful androgen than testosterone, especially when measured by the ventral prostate index. 

I7(x-Methyl-17 -hydroxy-estra-4,9,l l-trien-3-one (Methyltrienolone, N-99). In the course of a steroid total synthesis [293] this compound (Methyltrienolone, N-99) was prepared it was reported [55] to possess 6000% of the androgenic (ventral prostate index), 7500% of the androgenic (seminal vesicles index), and 12,000% of the anabolic (levator ani index) activity of methyltestosterone. Later the anabolic activity was reported [74] to be 30,000% of that of methyltestosterone. As measured by multiple parameters methyltrienolone turned out to be the most hepatotoxic steroid, causing biochemical symptoms of intrahepatic cholestasis [75]. It was also reported [74] to reduce the excretion of 17-ketosteroids and 17-hydroxycorticosteroids and to cause enhancement of the blood coagulation factors V, VII, and X. It also increases the prothrombin content of the plasma [74]. 

Methylene-l7a-methyl-l 7 -hydroxy-5a-androst-l-ene. Upon oral administration this compound (A-21), (E. Merck A.G., Darmstadt, Germany) showed [48] 266% of the anabolic activity and 12% of the androgenic activity of methyltestosterone. The anabolic-androgenic ratio of 22 represents a very favorable therapeutic index. 

Vermeulen A, Stoica T, Verdonck L. The apparent free testosterone concentration, an index of androgenicity. J Clin Endocrinol Metab 1971 33 759-67. 

The laboratory mouse can also be used for this purpose, except that its prostate is extremely small and comparatively large doses must be used for response, whereas, in contrast to the rat, its seminal vesicle appears to be somewhat more sensitive and is more generally employed as an androgenic end point. Here the weight of the kidney rather than the levator ani muscle is an index of anabolic activity (27). 

The levator ani muscle responds to some extent to androgens per se. Nitrogen retention studies are therefore preferred as a more valid index for anabolic activity. 

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