Steroids excretion

Aquatic organisms, such as fish and invertebrates, can excrete compounds via passive diffusion across membranes into the surrounding medium and so have a much reduced need for specialised pathways for steroid excretion. It may be that this lack of selective pressure, together with prey-predator co-evolution, has resulted in restricted biotransformation ability within these animals and their associated predators. The resultant limitations in metabolic and excretory competence makes it more likely that they will bioacciimiilate EDs, and hence they may be at greater risk of adverse effects following exposure to such chemicals. 

Rather voluminous data are now available regarding steroid excretion. These are all in line with the idea that there is a high degree of individuality28,29,30,31 though the individual patterns, especially of so-called "normals," have not often been studied. We have already referred p. 101) to the extensive and conclusive work of Dobriner and coworkers in which attention was paid to each individual s steroid excretion and in which it was shown that, when individual steroids are considered, extremely wide variations are present, and each individual s excretion constitutes a highly distinctive pattern. 

For space considerations we are not including here details regarding an SIM program used for profile analysis in the first days and weeks of life when steroid excretion is most different from that of older individuals [10, 80]. 

The quality assurance sample used is an aliquot of a urine pool prepared by mixing equal proportions of 24-h samples from 20 men and women. Thus, the values obtained on GC-MS analysis should approximate true average steroid excretions. We use these values to adjust the calibration of steroids without authentic materials in the external standard. We have determined that the excretion of 18-OH-THA in the quality assurance sample should be 90 pg/24 h THAldo, 30 pg/24 h, and 18-oxo-THF, 5 pg/24 h. The amount of these steroids in clinical samples is thus calibrated against a normal excretion. 

Table 5.3.5 Steroid excretions (/,ig/24 h) and diagnostic ratios in patients with 3fi-hydroxysteroid dehydrogenase type II (3(iHSD II) deficiency... 

Table 5.3.7 Steroid excretion in three patients with 17fiHSD deficiency...

Table 5.3.9 Steroid excretions and diagnostic ratios in five patients with ACRD...

Table 5.3.11 Steroid excretion and diagnostic ratios in infants with pseudohypoaldosteronism (PHA) and aldosterone synthase deficiency (ASD)...

Honour JW, Tourniaire J, Biglieri EG, Shackleton CHL (1978) Urinary steroid excretion in 17a-hydroxylase deficiency. J Steroid Biochem 9 495-505... 

Shackleton CH (1976) Congenital adrenal hyperplasia caused by defect in steroid 21-hydroxylase. Establishment of definitive urinary steroid excretion pattern during first weeks of life. Clin Chim Acta 67 287-298... 

Maskarinec G, Morimoto Y, Novotny R, Nordt FJ, Stanczyk FZ, Franke AA. 2005. Urinary sex steroid excretion levels during a soy intervention among young girls A pilot study. Nutr Cancer 52 22-28. 

Huff, M.W. and Carroll, K.K. 1980. Effects of dietary protein on turnover, oxidation, and absorption of cholesterol, and on steroid excretion in rabbits. J. Lipid Res. 21, 546-558. 

Imaizumi, K., Abe, K., Kuroiwa, C., and Sugano, M. 1993. Fat containing stearic acid increases fecal neutral steroid excretion and catabolism of low density lipoproteins without affecting plasma cholesterol concentration in hamsters fed a cholesterol-containing diet. J. Nutr. 123, 1693-1702. 

Nakamura, Y., Tsumura, Y., Tonogai, Y., and Shibata, T. 1999. Fecal steroid excretion is increased in rats by oral administration of gymnemic acids contained in Gymnema syhestre leaves. J. Nutr. 

Tanaka, K., Aso, B., and Sugano, M. 1984. Biliary steroid excretion in rats fed soybean protein and casein or their amino acid mixtures. J. Nutr. 114, 26-32. 

Adrenal Steroid Excretion in Rats in a Repeated Dose Study... 

During a treatment period of seven days or up 28 days (toxicology study), the excretion of corticosterone and of aldosterone during the night period is monitored on the last three days of treatment, or on two consecutive days of each week (toxicology study). This approach ensures a check on consistency of changes in adrenal steroid excretion. 

The core of this method is the assessment of adrenal steroid excretion during minimum invasive conditions, during repeated-dose administration of the test substance. 

A typical Western diet contains approximately 100-300 mg and 20-50 mg of plant sterol and plant stanol, respectively. The relationship between total dietary phytosterol content and the fatty acid composition of the diet decreases with increasing saturated fatty acids, whereas the total dietary phytosterol content increases with increasing PUFA (89). Fortification of lipid foods, such as margarine, with plant sterols will dramatically increase the daily intake of phytosterols and significantly lower serum cholesterol (90). The dietary consumption of large amounts of plant sterols will interfere with cholesterol absorption, thereby leading to an increased daily neutral steroid excretion. 

Kay, R.M. and Truswell, A.S. 1977. Effect of citrus pectin on blood lipids and fecal steroid excretion in man, Am. J. Clin. Nutr., 30 171-175. 

Thus, in infants, it is in the presence of a complex and changing normal pattern that any abnormality of steroid metabolism must be identified. Three media are available in reasonable quantity for investigation (1) a sample of amniotic fluid may be collected at birth, and since this contains steroids excreted in urine by the fetus, its contents may give an... 

Drayer and Giroud (D16) have shown that, although the proportion of steroids excreted in urine free is considerably increased in infants, sulfate conjugation is also increased, and for the 17-OHCS, sulfation is at least as important as conjugation with glucuronic acid (see Section... 

To elucidate the urinary steroid excretion pattern in various cases of the adrenogenital syndrome Bongiovanni (B28) used a long but excellent technique involving digitonin, and Girard separations, multiple chromatography on silica-gel and paper, and a variety of colorimetric techniques for detection and assay. 

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... 

Delayed maturation of zona glomerulosa Normal steroid excretion (other than aldosterone) and metabolites Low increasing to normal after first months or years of life ... 

Since the major steroids excreted by newborn infants have the 3j8-hydroxy-A structure (S9), and the excretion of these compounds is in-... 

Fia. 9. The urinary excretion of certain steroids in an infant with a deficiency of 21-hydroxylase. The filled-in columns indicate the steroid excretion while the infant was receiving therapy with cortisone and fluorocortisol. 21-OH-pregnenolone and pregnanetriol were identified by mass spectrometry. The unidentified compound reacts with blue tetrazolium and has a polarity similar to 21-OH-pregnenoIone. 

Urinary Steroid Excretion in 5 Newborn Infants Averaged for the First 3 Postnatal Days with No Treatment, and for Days 4, 5, and 6, DURING Which Corticotropin Was Administered"... 

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