A sex steroid-binding protein (SBP) that binds to 17 b-estradiol with high affinity and moderate capacity was identified in the plasma of female and juvenile of kutum (Rutilus frisii kutum) sampled during the early stage of gonadal maturation in October and prior to spawning in March. Mean maximum specific binding (Bmax) and equilibrium dissociation constant (Kd) of the fish were as follows: In...

the correlation between serum steroid hormones, testosterone (t), 17β-estradiol (e2), and progesterone (p) and weight of female fishes, biological characteristics of gonad (e.g. fertilization rate, fluid egg rate, gonadosomatic index , polarization index and oocyte diameter) in 10 female of the migratory population of sterlet (acipenser ruthenus) and 5 female of the migratory population of sibe...

To study the effects of environmental endocrine disruptor compounds (EDCs) on aquatic animals, embryos and larvae are typically incubated in water containing defined concentrations of EDCs. However, the amount of EDC uptake into the animal is often difficult to determine. Using radiolabeled estradiol ([3H]E2), we previously developed a rapid, straightforward assay to measure estradiol uptake fr...

Previous studies have demonstrated that 17 beta-estradiol (E2) causes a 3-fold increase in epidermal growth factor (EGF) receptors in uterine membranes. We now report that the increase in uterine EGF receptor levels is due to an increase in the steady-state levels of EGF receptor mRNA. After a single E2 injection, EGF receptor mRNA levels, as determined by RNA blots, increase 3- to 4-fold betwe...

Risk assessments for nongenotoxic chemicals assume a threshold below which no adverse outcomes are seen. However, when an endogenous chemical, such as 17ss-estradiol (E2), occurs at a concentration sufficient to cause an effect, the threshold is already exceeded. Under these circumstances, exogenous estradiol is not expected to provide a threshold dose. This principle is demonstrated for E2 in ...

The beneficial effect of dietary soy food intake, especially for women diagnosed with breast cancer, is controversial, as in vitro data has shown that the soy isoflavones genistein and daidzein may even stimulate the proliferation of estrogen-receptor alpha positive (ERα+) breast cancer cells at low concentrations. As genistein and daidzein are known to inhibit key enzymes in the steroid metabo...

Intravaginal impedance (IVI) fluctuates during the goat estrous cycle. To understand which ovarian steroids are responsible for IVI changes and whether IVI variations are associated with precopulatory and copulatory behaviors, 8 ovariectomized females were assigned to 4 treatments in a 4 x 4 Latin square replicated over four 8-d periods. The treatments were as follows: progesterone plus estradi...

Aim . To study the possible synergistic action of steroid hormones and hormone-specific autoantibodies anti-autoantibodies in conversion ER+/PR+ tumors into ER-/PR- breast cancer patients. Materials Methods Concentrations estradiol (E2) progesterone (Pg) levels idiotypic IgA antibodies (IgA 1 -E2 -Pg) as well anti-idiotypic IgG (IgG 2 were studied serum 979 patients (432 with stage 547 stages 2...