The aim of the present research was to study the role of angiotensin-converting enzyme (ACE) and ANG II in amphibian ( Rana esculenta) testicular steroidogenesis and prostaglandin production. Hormonal effects of ACE, ACE inhibitors, synthetic bullfrog ANG I, and [Val5]ANG II were determined in frog testis of prereproductive period. Production of 17β-estradiol, progesterone, androgens, and PGE2 ...

Previous reports correlate plasma levels of estrogen with increased nitric oxide (NO) production. To investigate whether the hemodynamic effects of estrogens are mediated by NO, we compared the hemodynamic changes induced by 17β-estradiol (100 μg/kg) in the absence and presence of the NO synthesis inhibitor N ω-nitro-l-arginine methyl ester (l-NAME). All protocols were performed in ovariectomiz...

Steroid hormones, such as 17β-testosterone, 11-ketotestorenone and 17β-estradiol, play an essential role not only in reproductive function but also are potential biomarkers of numerous additional functions teleost fish. The presence endocrine disruptor compounds aquatic ecosystems has raised concern about their effect on hormone levels fish target organs. Since hormones present very low concent...

Sex steroids in general and estrogens in particular – in addition to their effects on the reproductive organs – affect a large number of crucial bodily functions, including “higher” brain functions. Neuropeptides constitute the phylogenetically oldest neurotransmitter system and are currently thought to act mainly during stress, disease or injury. The concentration of galanin is i.a. up-regulat...

Abstract Two solvent mixtures for high-performance thin-layer chromatographic (HPTLC) separation of some compounds showing estrogenic activity in the yeast estrogen screen (YES) assay are presented. The new method, planar (pYES) combines YES and a on silica gel HPTLC plates with performance assay. For separation, analytes were applied bandwise to (10 × 20 cm) fluorescent dye (Merck, Germany). d...

BACKGROUND/AIMS To study serum testosterone and estradiol in healthy boys in relation to growth during puberty up to peak height velocity (PHV). METHODS Growth velocity was analyzed through testosterone (n = 41) and 17β-estradiol (n = 37) 24-hour profiles in a dose-response model. Participants were 26 healthy boys admitted for short or tall stature or participating as healthy volunteers at th...

The purpose of this in vitro study was to assess the effect of 17β-estradiol on hemorheologic parameters, namely on erythrocyte aggregation and deformability and membrane fluidity. Blood samples from 65 women (aged 57±4 years) undergoing postmenopausal hormone replacement therapy were obtained and were incubated for 5 min in absence and presence of 17β-estradiol 10−5 M. The measured parameters ...

Two hydrosoluble conjugates of 17β-estradiol (ED) and estradiol-17β-valerate (EV) with polyaspartamide polymer were prepared and characterized. ED and EV were first chemically modified and bound to poly[α,β-(N-2-hydroxyethyl-DL-aspartamide)]-poly[α,β-(N-2-aminoethyl-DL-aspartamide)] (PAHA), a hydrosoluble polyaspartamide-type copolymer bearing both hydroxyl and amino groups. ED was first conver...