Testosterone INDEX

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. 

This index is a ratio of testosterone and SHBG multiplied by 100 to give concentrations similar to measured free testos-... 

Nanjee MN, Wheeler MJ, Plasma free testosterone—Is an index sufficient Ann Clin Biochem 1985 22 (Pt4) 387-90,... 

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

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. 

One of the best efforts to compare the anabolic activity of many steroids which have been discussed is that of Albanese and coworkers (1), who devised a careful means of comparing a wide series of steroids. They employed nitrogen balance studies in appropriate patients. They then expressed the steroid protein activity index, the SPAI, on a comparative basis. The antianabolic or catabolic adrenal cortical steroids all have negative values by this assay. Table II shows comparative SPATs of seven of the steroids which have been discussed. It can be seen by this index that testosterone propionate is the least active and stanozolol the most active. Further reports from Albanese and coworkers will be anticipated with interest. 

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. 

One of the issues with P450 3A4 is which reaction provides the most appropriate index of activity, both in vitro and in vivo. Historically nifedipine oxidation and testosterone 6p-hydroxy-lation were among the first activities identified and are still used in vitro K Midazolam 1 -hydrox-ylation has also been used , in part because of its acceptance for in vivo assays. 

The current version of this approach uses N x N matrices (N being the number of molecules included in the data set), in which the 3D similarity indices of each molecule as compared to every other molecule of the whole set are the non-diagonal elements of the similarity matrix [1064, 1065]. In an application to the affinities of 31 steroids to corticosteroid- and testosterone-binding globulins (same data as used in CoMFA studies, e.g. [36]), Carbo index similarity matrices were calculated for the shape and the electrostatic potentials of all molecules. Using the similarity... 

Beteringe et al. synthesized and separated by TLC the Z and E diasteroisomers of the 0-methyloximes of testosterone and 17a-methyltestosterone. These compounds were characterized by the Pyka index /sti, the... 

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