Ergosterol derivatives exhibited copious promising biological activities. The fungus Gyromitra esculenta is widely distributed in Europe and North America. In order to examine the chemical properties of esculenta, a phytochemical study has been preceded resulted isolation steroid, ergosta-5, 22-dien-3β-ol (brassicasterol), from its methanol extract. complete identification absolute configuratio...

SYNOPSIS. Current risk assessment techniques for almost all chemicals involve establishing a threshold dose, or the dose below which no adverse effects are seen. But threshold doses may not apply in situations where the chemical mimics the actions of an endogenous compound—such as a steroid hormone—that is important to development. In such cases, any exposure may exceed the threshold. Recent st...

The de novo production of estrone and estradiol by the fetal and infantile rat ovary and its regulation by cAMP, LH and FSH were investigated. Basal estrogen secretion was not demonstrable before d 5 after birth. However, the fetal ovary was responsive to cAMP as early as 14 d old. Estrone was the main estrogen secreted. Steroid aromatase inhibitors inhibited cAMP-stimulated estrone secretion. ...

Prostate cancer is a hormone-dependent cancer and its proliferation is stimulated by endogenous steroid hormones. Aromatase (CYP19) and 5a-reductase (SRD5A) are the key enzymes that synthesize these hormones. Aromatase converts androgens to estrogens and 5a-reductase converts testosterone to dihydrotestosterone. Natural compounds present in the Trichosanthes cucumerina L. delay prostate cancer ...

In recent years, there has been increasing recognition of the importance of steroid aromatization in organs besides the steroidogenic ones. Estrogens formed from C-19 precursors in peripheral tissues can clearly contribute to the levels of estrogens in the circulation, while aromatization in target cells may be an important determinant of the concentration of estrogens to which a particular pop...

INTRODUCTION Evidence collected over the years has demonstrated that cryptorchidism is associated with a defect in spermatogenesis and, as a consequence, with either reduced fertility or infertility. However, the effect of cryptorchidism on Leydig cell function is less clear. The aim of our study therefore was to investigate the regulation of steroid hormone biosynthesis and, additionally, inte...

The effects of salmon calcitonin (sCT) on the secretion of 17beta-estradiol (E(2)) were examined in female common carp, Cyprinus carpio. Vitellogenic stage fish adapted to high-Ca water were i.p. injected with vehicle, sCT, human chorionic gonadotropin (hCG), or hCG plus sCT. To determine whether ovarian follicles are equipped with CT receptors, a CT binding assay was conducted. In the in vitro...