Testosterone catabolism

Mobus E, M Jahn, R Schmid, D Jahn, E Maser (1997) Testosterone-regulated expression of enzymes involved in steroid and aromatic hydrocarbon catabolism in Comamonas testosteroni. J Bacteriol 179 5951-5955. 

The catabolism of plasma testosterone and other androgens occurs primarily in the liver (Fig. 63.3), where they are conjugated into water-soluble compounds that are excreted by the kidney as the urinary 17-ketosteroids. 

Anabolic activities of testosterone, such as increases in amino acid incorporation into protein and in RNA polymerase activity, have been demonstrated in skeletal muscle. Apart from the direct anabolic effects in specific tissue, androgens antagonize the protein catabolic action of glucocorticoids. The androgen compounds with the greatest ratio of protein anabolic effects to virilizing effects are the 19-nortestosterone derivatives. Compounds that are used clinically (Table 63.3) include nandrolone phenpropionate (Durabolin), nandrolone decanoate... 

The use of HCG/Clomid was quite prudent since Anadrol-50, Testosterone Enanthate, and Dianabol all decreased HPTA function. The use of Clenbuterol for atleast 4 weeks was just as prudent since catabolism is of concern during this post-cycle period. Anadrol-50, Parabolan, and Dianabol are all very liver toxic, while Winstrol Depot is moderately liver toxic in the listed reported dosage range. 

Testosterone Propionate, Winstrol Depot, Durabolin, Deca Durabolan, even Parabolan if I could find it. I stacked one or more of these together with the rest of my cycle gear and added an AAS that worked well in a catabolic environment, preferably Primobolan Depot. 3 weeks with high AAS dosages was my max for site injection. 

It has been suggested that the protein catabolism of injury is due to the diminished activity of the anabolic hormones, testosterone and... 

Natural testosterone has poor oral bioavaUabdity because of extensive first-pass hepatic metabolism, and large doses must therefore be taken. To improve oral bioavaUability, alkylated derivatives were formulated. Of these, methyltestosterone and fluoxymesterone are more resistant to hepatic catabolism, and can be taken in smaller daily doses, which are potentially safer. However, oral alkylated derivatives of testosterone are associated with a higher incidence of serious hepatotoxicity, and therefore are not preferred for management of sexual dysfunction. 

Intense training increases testosterone, GH and IGF levels. However it also decreases insulin levels and increases cortisol (the catabolic muscle breakdown hormone)... 

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. 

Fluoxymesterone promotes growth and development of male reproductive organs, maintains secondary sex characteristics, increases protein anabolism, and decreases protein catabolism. It is used for replacement therapy in conditions associated with symptoms of deficiency or absence of endogenous testosterone delayed puberty (men) palliation of androgen-responsive recurrent mammary cancer in women who are more than 1 year but less than 5 years postmenopausal (women). 

Because of its anabolic effects, testosterone has been used to ameliorate catabolic and muscle-wasting states, generally without benefit. One exception is in the treatment of muscle wasting associated with acquired immunodeficiency syndrome (AIDS), which often is accompanied by hypogonadism. Treatment of men with AIDS-related muscle wasting and subnormal serum testosterone concentrations increases their muscle mass and strength. 

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