Testosterone steroid excretion

Congenital adrenal hyperplasia 21-Hydroxylase with and without salt loss High 17-08 excretion High 3/S-hydroxy-A steroid excretion (infants) High pregnanetriol excretion High testosterone excretion -1- Normal or low Normal or low... 

The major pathway for the degradation of testosterone in humans occurs in the liver, with the reduction of the double bond and ketone in the A ring, as is seen in other steroids with a A4-ketone configuration in the A ring. This leads to the production of inactive substances such as androsterone and etiocholanolone that are then conjugated and excreted in the urine. 

T FIGURE 10-19 Steroids derived from cholesterol. Testosterone, the male sex hormone, is produced in the testes. Estradiol, one of the female sex hormones, is produced in the ovaries and placenta. Cortisol and aldosterone are hormones synthesized in the cortex of the adrenal gland they regulate glucose metabolism and salt excretion, respectively. Prednisolone and prednisone are synthetic steroids used as antiinflammatory agents. 

Testosterone This agent is ineffective orally because of inactivation by first-pass metabolism. As with the other sex steroids, testosterone is rapidly absorbed by the liver and other tissues, and is metabolized to relatively or completely inactive compounds that are excreted primarily in the urine but also in the feces. Testosterone and its C-17-esters (for example, testosterone cypi-onate or enanthate) are administered intramuscularly. [Note The addition of the esterified lipid makes the hormone more lipid-soluble, thereby increasing its duration of action.] Testosterone and its esters demonstrate a 1 1 relative ratio of androgenic to anabolic activity. 

I) Consider three structurally similar Cis steroids —testosterone, an-drostenedione, and dehydroepiandrosterone. Each of these compounds is secreted into the blood stream by glands, and after provoking its biochemical effect, is metabolized and excreted. If the only source of the plasma pool were provided by the glandular secretion of the hormone, then the secretion rate would be used to calculate the plasma concentration. However, the picture in the case of the three Ci steroids is complicated by the fact that the three compounds are peripherally interconvertible. Since both glandular secretion and peripheral conversion of precursors contribute to the plasma pool, the production rate is used to... 

Injected as an oil, androgens are so quickly absorbed, metabolized, and excreted that the effect is very small. Esters of testosterone are more slowly absorbed and are more effective. The majority of the androgens is inactivated primarily in the liver and involves oxidation of the hydroxy groups and reduction of the steroid ring. Alkylation at the 17-position retards hepatic metabolism and hence is effective orally. 

The main excretory metabohtes of androstenedione, testosterone, and DHEA are shown in Figure 53-5. Except for epitestosterone, these catabolites constitute a group of steroids known as 17-ketosteroids (17-KSs). These metabolites are excreted primarily in the urine (>90%), with approximately half as 17-KSs, and half as diols, triols, conjugates, and other polar compounds." ... 

The 17-KSs are metabolites of precursors secreted by the adrenal glands, the testes, and to some extent the ovaries. In men, approximately one third of the total urinary 17-KSs represent metabolites of testosterone secreted by the testes, whereas most of the remaining two thirds are derived from the steroids produced by the adrenal glands. In women, who normally excrete smaller quantities than men, the total 17-KS concentrations are derived almost exclusively from the adrenal glands. 

An epimer of testosterone, epitestosterone (17a-hydro-xylated testosterone), is produced by the testes and excreted as such in the urine in amounts approximately equal to that of testosterone(T epiT 1 1). Epitestosterone is biologically inactive, but it is not a metabolite, and is believed to be produced only by the gonads thus, it is used as a gonadal steroid marker. In women, the ratio of T to epiT is also normally 1 1. Urinary T epiT is useful in monitoring abuse of anabolic steroids by athletes because the ratio increases when any exogenous testosterone derivative is used. 

In Table 2 the major metabolites of the steroid sex hormones and some important related steroids are listed. Their relationships to their precursors are in some cases controversial at present and will be discussed in the next section of this article. Suffice it to say at the moment that simple relationships between the excretion rates of some of these metabolites and the secretion rates of their precursors are not easy to establish. On the other hand, it is fair to add that some of the complexities implied by recent work on the metabolism of testosterone and andros-tenedione, and on the metabolic activity of the placenta and fetus in pregnancy should not be allowed to obscure the relative simplicity of many aspects of the metabolism of progesterone and of estrogens. 

In males testosterone is manufactured and secreted overwhelmingly by the testes. After secretion, 97 percent of testosterone is boxmd by protein carriers in blood and circulates in the body for thirty to sixty minutes. At this point, it has either been absorbed by varions tissnes or degraded to inactive molecules. Much of the testosterone absorbed by tissues is reduced to dihydrotestosterone, a step that is essential for the actnalization of some of testosterone s effects. Testosterone not absorbed by tissues will be degraded by the liver, and the prodncts of this degradation will be excreted from the body, see also Estrogen Steroids. 

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