Psychiatry related information on Epitestosterone

• Athletes are considered to be positive for drug abuse if the urinary testosterone to epitestosterone ratio is greater than 6 [1].

High impact information on Epitestosterone

• A double isotope ratio technique was used to estimate the specific binding of testosterone (T), as opposed to its biologically nonactive stereoisomer, epitestosterone (Epi T) [2].
• However, daily injections of physiological doses of dexamethasone (4 micrograms/mouse) or high doses of epitestosterone, progesterone, or cholesterol (200-5000 micrograms/mouse) did not enhance the tumor growth in castrated mice [3].
• Mass spectral analysis of the C-16 hydroxylation products from incubations of testosterone or epitestosterone in 18O2 shows essentially complete incorporation of 18O (greater than 95%) [4].
• In women, epitestosterone exhibited a maximum around 20 yr of age, followed by a continuous decline up to menopause and by a further increase in the postmenopause [5].
• Determination of the ratio (14C) testosterone: (3H) epitestosterone in the successive fractions of various ultracentrifuged preparations showed a small but significant preference for (14C) testosterone by human and bovine serum albumin, while alpha1-acid glycoprotein had a preference for (3H) epitestosterone [6].

Biological context of Epitestosterone

• After parturition the concentrations of epitestosterone and oestrogens declined rapidly in all groups [7].
• Further studies showed that a complex action consisting of competitive binding of epitestosterone to androgen receptor, of inhibition of testosterone biosynthesis and its reduction to dihydrotestosterone and of antigonadotropic activity could be demonstrated in rat, mice and human tissues [8].
• Impaired hydrolysis of circulating epitestosterone sulphate by deficiency of a specific sulphatase acting on 17 alpha-sulphates must also be considered as a possible reason for the decreased availability of epitestosterone for hepatic glucuronidation [9].
• Other steroids (17 alpha-testosterone, 17 alpha-estradiol, and 17 beta-estradiol, DHT, and progesterone) tested under the same experimental conditions had no effect on sperm motility, but cottonseed oil (goosypol) had drastic effects [10].
• In LNCaP/FGC cells cultivated with fetal calf serum (FCS) treated with dextran-coated charcoal epitestosterone displayed rather androgenic than antiandrogenic properties, whereas the cultivation with native FCS resulted in a very weak inhibition of tumour cell growth with epitestosterone in higher concentration [11].

Anatomical context of Epitestosterone

• The aromatization of epitestosterone (17 alpha-hydroxy-4-androsten-3-one) and testosterone by lyophilized human placental microsomes was studied [12].
• Epitestosterone significantly inhibited the T-dependent stimulation of pigment, sebaceous gland, and hair follicle at either 5- and/or 10-fold excess doses [13].
• CONCLUSION: The testes are the major source of epitestosterone, the adrenal contribution being relatively modest [14].
• Measurement of arteriovenous differences at term indicated that epitestosterone was secreted by the uterus; its production was not dependent on the presence of corpora lutea [15].
• Steroidal antiandrogen epitestosterone was administered to intact male mice and its effect on seminal vesicles, kidney, femoral bones and circulating calcium, phosphate, testosterone and LH were compared with controls and castrated animals [16].

Associations of Epitestosterone with other chemical compounds

• Two related steroids, 5 beta-DHT and 17 alpha-epitestosterone, did not inhibit the action of hPTH [17].
• In comparison with wild-type rat androgen receptor in prostate, the receptor in LNCaP cells has altered affinity for a number of steroids or analogs such as progesterone (R5020), antiprogesterone (RU486), two antiandrogens (cyperoterone acetate and hydroxyflutamide), and an androgen metabolite (epitestosterone) [18].
• Secretion by the human testis of epitestosterone, with its sulfoconjugate and precursor androgen 5-androstene-3 beta,17 alpha-diol [19].
• Inhibition of steroid 17 alpha-hydroxylase and C17,20-lyase in the human testis by epitestosterone [20].
• The maternal concentrations of both epitestosterone and unconjugated oestrogens (mostly oestradiol-17 alpha) in the blood increased before parturition and dropped post partum [15].

Gene context of Epitestosterone

• The endogenous anti-androgen, epitestosterone, also showed a slight neuroprotective effect but not through the androgen receptor [21].
• No differences were detected in serum LH, FSH, epitestosterone and sex hormone binding globulin (SHBG) [22].
• Correlations between age and IGF-1 (r = -0.281, p<0.05), age and serum epitestosterone (r = -0.261, p<0.05), estradiol and testosterone (r = 0.367, p<0.01), and between estradiol and epitestosterone (r = -0.414, p<0.001) were found [23].
• Comparative studies of the aromatization of testosterone and epitestosterone by human placental aromatase [12].
• Cis-testosterone was unable to cause the nuclear accumulation of the estrogen receptor at all concentrations studied [24].
• Our data indicate that 5-androstene-3beta, 17alpha-diol is an important precursor of epitestosterone and that CYP17 is involved in its production [25].

Analytical, diagnostic and therapeutic context of Epitestosterone

• Nine of 10 athletes' urine samples with epitestosterone concentrations >180 microg/L (624 nmol/L) had delta(13)C values within +/- 3 SD of the control group [26].
• Detection of simultaneous self-administration of testosterone and epitestosterone in healthy men [27].
• Lyophilization of fresh microsomes or storage of the lyophilized microsomes at -20 C greatly reduced the aromatizing activity upon epitestosterone but not upon testosterone [12].
• In the present study the epitestosterone level in human plasma was determined by a specific radioimmunoassay and the concentration of epitestosterone was established in age groups of males of 6 to 65 years of age [28].
• Direct measurement of urinary testosterone and epitestosterone conjugates using high-performance liquid chromatography/tandem mass spectrometry [29].

References