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Glutathione transferases (GSTs) comprise a superfamily of enzymes prominently involved in detoxication by making toxic electrophiles more polar and therefore more easily excretable. However some GSTs have developed alternative functions. Thus, a member of the Alpha class GSTs in pig and human tissues is involved in steroid hormone biosynthesis, catalyzing the obligatory double-bond isomerization of Δ 5 -androstene-3,17-dione to Δ 4 -androstene-3,17-dione and of Δ 5 -pregnene-3,20-dione to Δ 4 -pregnene-3,20-dione on the biosynthetic pathways to testosterone and progesterone. The human GST A3-3 is the most efficient steroid double-bond isomerase known so far in mammals. The current work extends discoveries of GST enzymes that act in the steroidogenic pathways in large mammals. The mRNA encoding the steroid isomerase GST A3-3 was cloned from testis of the horse ( Equus ferus caballus). The concentrations of GSTA3 mRNA were highest in hormone-producing organs such as ovary, testis and adrenal gland. EcaGST A3-3 produced in E. coli has been characterized and shown to have highly efficient steroid double-bond isomerase activity, exceeding its activities with conventional GST substrates. The enzyme now ranks as one of the most efficient steroid isomerases known in mammals and approaches the activity of the bacterial ketosteroid isomerase, one of the most efficient enzymes of all categories known today. The high efficiency and the tissue distribution of EcaGST A3-3 support the view that the enzyme plays a physiologically significant role in the biosynthesis of steroid hormones. [ABSTRACT FROM AUTHOR]

In this study, the human H295R adrenocarcinoma cell line was exposed to different concentrations (0.04, 0.2, 1.0, 2.5 or 5 µg/mL) of nonylphenol (NP) to investigate its impact on the inhibition or induction of the steroid hormones production during 48 h ofin vitroculture. The hormone production was measured using ELISA kits. Results of thisin vitrostudy suggest various effect of nonylphenol in relatively low concentrations on the selected steroid hormones production by the human H295R adrenocarcinoma cell line. The inhibiting impact on progesterone and androstenedione production was observed. The amount of progesterone was significantly decreased at 1.0, 2.5 and 5 µg/mL NP. Equally, the androstenedione production significantly decreased at 5 µg/mL NP. On the other hand, the amount of testosterone and 17β-estradiol was induced after nonylphenol exposition. The significant increase of testosterone level was found out at treatment with 5 µg/mL NP. 17β-estradiol production significantly increased at the doses of 2.5 and 5 µg/mL NP. [ABSTRACT FROM PUBLISHER]

Abstract: The annual killifish, Austrofundulus limnaeus, typically enters embryonic diapause at two distinct points of development, termed diapause II and III. This study explores the role of maternal and embryonic steroid hormones, including 17-β-estradiol (E2), androstenedione (A4) and testosterone (T), in regulating the developmental decision to enter or escape diapause II. Steroid hormone levels were measured in tissues isolated from adult female killifish during the normal lifespan of this species and in individuals of the same age that were producing either high or low proportions of escape embryos. Levels of steroid hormones were also measured during early development and in fertilized eggs that were predicted to be on either an escape or diapausing developmental trajectory. Decreases in maternal E2 levels associated with age are correlated with decreasing escape embryo production. Maternal production of escape embryos is correlated with increased ratios of E2 to T in adult ovary tissue. Interestingly, neither hormone is significantly different in fish producing embryos on different developmental pathways when examined independently. Levels of steroid hormones in fertilized eggs are not correlated with entry or escape from diapause II, though levels of A4 tend to be higher in escape embryos. Escape embryos exhibit faster hormone metabolism and earlier hormone synthesis than embryos that will enter diapause II. Incubation of embryos in exogenous E2 is associated with a 7-fold increase in escape embryo production, and significantly elevated A4 levels. These data suggest that steroid hormones may be critical factors involved in determining developmental pathways in embryos of A. limnaeus. [Copyright &y& Elsevier]

Reference plasma adrenal steroid levels during early infancy are frequently used to verify hormone measurements when any adrenal abnormality is suspected. We aim to obtain longitudinal reference plasma levels for 17-hydroxyprogesterone (17OHP), 11-desoxycortisol (11DOC), cortisol, dehydroepiandrosterone sulfate (DHEAS), testosterone, and androstenedione in healthy infants from birth to 6 months of age. In 138 term infants, 80 males and 58 females, plasma steroid levels were measured using specific RIA procedures at birth and on the 3rd, 15th, 30th, 60th, 90th, 120th, 150th, and 180th days of life. Smoothed percentiles for each variable were calculated according to the LMS method (LMS program version 1.16, Institute of Child Health, London). Except for cortisol, plasma levels of adrenal steroids decreased progressively from birth to 6 months of age. Plasma concentrations of 17OHP, 11DOC, and cortisol did not show gender differences, but testosterone and androstenedione were significantly higher in boys, and DHEAS levels were higher in girls. Longitudinal reference plasma levels for 17OHP, 11DOC, cortisol, DHEAS, testosterone, and androstenedione have been described in an adequate sample of healthy infants from birth to 6 months of age. These standards, displayed as smoothed percentiles, may be used as reference values in the management of congenital endocrine (adrenal or gonadal) abnormalities that appear in the first weeks of life. [ABSTRACT FROM AUTHOR]

: ObjectiveTo determine if insulin or glucose action plays a role in adrenocortical steroidogenesis in the polycystic ovary syndrome (PCOS).: DesignProspective cohort study.: SettingAcademic medical center.: Patient(s)Nine reproductive-aged patients with PCOS and nine age-, race-, and body mass index–matched controls.: Main outcome measure(s)Insulin-modified frequently sampled intravenous glucose tolerance testing and an acute 60-minute ACTH-(1-24) stimulation test. From the glucose tolerance test, glucose and insulin were measured and the insulin sensitivity index, glucose effectiveness, and acute insulin response to glucose were determined. Dehydroepiandrosterone sulfate (DHEAS) basally and 17-hydroxypregnenolone, 17-hydroxyprogesterone, DHEA, androstenedione, and cortisol during ACTH testing at 0 and 60 minute (steroid0 and steroid60) were determined. The net change in steroid during the ACTH test was calculated.: Result(s)The insulin sensitivity index had limited correlation with adrenocortical variables in both groups. In patients with PCOS, glucose effectiveness was positively associated with DHEAS, cortisol0, cortisol60, change in cortisol, DHEA0, DHEA60, change in DHEA, 17-hydroxyprenenolone60, change in 17-hydroxypregnenolone, DHEA0, androstenedione0, 17-hydroxyprenenolone0, 17-hydroxyprogesterone0, 17-hydroxyprenenolone60, and 17-hydroxyprogesterone60.: Conclusion(s)Adrenocortical biosynthesis, basally and in response to ACTH, appears to be closely associated with glucose effectiveness in PCOS. A common factor determining both the effectiveness of glucose to control its own production or uptake and adrenocortical biosynthesis may be aberrant in PCOS. [Copyright &y& Elsevier]