Oviduct nuclei from laying hens, or from chicks given an optimal dose of estrogen, contain receptors with a high affinity for 17beta-estradiol (apparent Kd of about 3.7 nM) at a concentration of about 10,600 molecules per tubular gland cell. Chicks withdrawn from estrogen stimulation exhibit a 7-fold lower level of nuclear estrogen receptors. Radioimmunoassay of 17beta-estradiol in the serum in...

Overexpression of epidermal growth factor receptor (EGFR) is correlated with loss of estrogen receptor and poor prognosis in breast cancer. To investigate this phenomenon, we transfected a cytomegalovirus expression vector directing the expression of EGFR into estrogen receptor-positive MCF-7 breast cancer cells and into a clone of MCF-7 cells previously transfected with transforming growth fac...

Vascular endothelial growth factor (VEGF) is a molecule implicated in the pathogenesis of several eye diseases. In this experimental study, we planned to evaluate the effects of surgical menopause and hormone replacement therapy on VEGF levels. Thus, we studied the effects of treatments involving estrogen, estrogen and progesterone (E/P) in combination, and genistein, which is a selective estro...

Background: Tubal ligation is one of the most common contraceptive methods in the world. Some researchers believe that tubal ligation has complications. It is assumed oxidative stress can produce these complications. The aim of this study was to evaluate oxidative stress and ovarian function after tubal ligation. Materials and Methods: In this study, female rats (weighting 200-250 g) were divid...

The possibility that estrogen status modulates total homocysteine concentration, a risk factor for vascular occlusion, was examined in a representative sample of the US population, the Third National Health and Nutrition Examination Survey (phase 2), 1991-1994. The geometric mean serum total homocysteine concentration was compared among population subgroups differing on inferred estrogen status...

OBJECTIVE In this study, we examined changes in serum leptin levels during the estrus cycle and the role of estrogen in these changes. METHODS We measured serum leptin levels during normal estrus cycles in intact rats and estradiol-17beta (E2)-induced artificial estrus cycles in ovariectomized rats. RESULTS Serum leptin levels increased 1.6-fold from 4.2 +/- 0.2 ng/ml during diestrus stage ...