The control of placental hormone biosynthesis is critical during gestation, since their coordinated action is essential for the normal progress of pregnancy. Hormonal synthesis regulation in placenta is still not elucidated and differs from that observed in other steroidogenic tissues since specific tropic hormones have not yet been identified. Cellular localization of growth factors in the pla...

Several synthetic aromatase inhibitors are currently in clinical use for the treatment of postmenopausal women with hormone-receptor positive breast cancer. However, these treatments may lead to untoward side effects and so a search for new aromatase inhibitors continues, especially those for which the activity is promoter-specific, targeting the breast-specific promoters I.3 and II. Recently, ...

Sexual behaviors in green anoles are regulated by steroid hormones. Androgens activate the display of masculine courtship and copulatory behaviors, and estradiol activates feminine receptivity. Testosterone can also facilitate receptivity in females. The present study was conducted to test the role of converting testosterone to estradiol (aromatization) in the regulation of sexual and aggressiv...

We evaluated the impact of maternal drug abuse at term on human placental cytochrome P450 (CYP)-mediated (Phase I) xenobiotic and steroid-metabolizing activities [aromatase, 7-ethoxyresorufin O-deethylase (EROD), 7-ethoxycoumarin O-deethylase (ECOD), pyrene 1-hydroxylase (P1OH), and testosterone hydroxylase], and androstenedione-forming isomerase, NADPH quinone oxidoreductase (Phase II), UDP-gl...

Sex steroid hormones such as estrogens and androgens are involved in the development and differentiation of the breast tissue. The activity and concentration of sex steroids is determined by the availability from the circulation, and on local conversion. This conversion is primarily mediated by aromatase, steroid sulfatase, and 17β-hydroxysteroid dehydrogenases. In postmenopausal women, this is...

CONTEXT There is a need for increased knowledge about endogenous sex hormone levels and clinical outcomes of risk/benefit. Immunoassays have poor specificity to reliably measure low steroid concentrations in elderly. OBJECTIVE The objective of the study was to evaluate plasma steroid concentrations with regard to prevalent cardiovascular disease (CVD) in elderly, using mass spectrometry. SE...

OBJECTIVE To evaluate the placental activity of steroid sulfatase (STS), 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD-1) and P450 aromatase (P450arom) in polycystic ovarian syndrome (PCOS) compared to normal pregnant women. DESIGN Twenty pregnant women with PCOS and 30 control pregnant women who delivered at term were studied. Samples of placental tissue and cord blood were obtained after d...

The ultrastructure of testicular cells of adult male African clawed frogs (Xenopus laevis) exposed to either estradiol (0.1 microg/L) or 2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine (atrazine; 10 or 100 microg/L) was examined by electron microscopy and compared to plasma concentrations of the steroid hormones, testosterone (T) and estradiol (E2), testicular aromatase activity and gonad gr...

Sex steroids are major drivers of sexual development and also responsible for the maintenance of the established gender. Especially fishes exhibit great plasticity and less conservation in sex determination and sexual development compared to other vertebrate groups. In addition, fishes have a constant sex steroid production throughout their entire lifespan, which makes them particularly suscept...