The hypothalamo-pituitary-adrenal (HPA) axis is modulated by sex hormones. Few data exist on the relation between acute estrogen deficit and HPA axis response to corticotropin-releasing hormone (CRH). The effects of a sudden drop in estradiol levels on basal and CRH-stimulated levels of ACTH, cortisol, testosterone, androstenedione and 17-hydroxyprogesterone (17-OHP) were assessed in nine preme...

Growth hormone (GH) and estrogen are essential stimulators of mammary cell proliferation and mammary development as mammals near puberty. Mammary ductal growth requires modifications of the extracellular matrix (ECM) for this tissue expansion to occur. Our purpose was to evaluate the effects of exogenous GH and ovariectomy (known to impact estrogen production) on gene expression of selected ECM...

The mare is the only non-primate species known to display estrous signs after ovariectomy and adrenal hormones have been implicated as a possible cause. Moreover, in several species, estradiol seems to have a stimulatory effect on the hypothalamic-pituitary-adrenal axis. The aim of the present study was to compare the effect of ACTH (tetracosactide) on pertinent hormones [cortisol, progesterone...

Oral estrogen treatment increases thrombotic risk. Tissue factor (TF), tissue factor pathway inhibitor (TFPI), and platelet interaction with leukocytes are important determinants of thrombogenesis. Therefore, the present study was designed to define and compare platelet TF and TFPI mRNA and adhesion protein expression in platelets derived from animals treated with different types of oral estrog...

We compared the effect of treatment with strength training (ST) and raloxifene (RALOX) on bone weight, blood glucose, lipid, antioxidant profile in ovariectomized rats. Twenty-four Wistar rats were distributed into four groups: ovariectomy + VEHICLE (control); RALOX; ST; RALOX ST. Thirty days after ovariectomy, animals underwent (750 μcg day-1) and/or ST (three sessions week-1). after, all grou...

Differences in the aggregation and release of growth factors including matrix metalloproteinases (MMPs) after loss of ovarian hormones could contribute to an exaggerated response to injury in arteries of ovariectomized animals. Therefore, experiments were designed to compare aggregation, dense granular ATP release, expression of MMPs (MMP-2, MMP-9, and MMP-14) and tissue inhibitors of metallopr...

We studied effect of pregnancy and ovariectomy on the development of mammary tumors in homozygous female HER-2/neutransgenic mice. The mean life span of uniparous mice was decreased by 16% in comparison to the control (P<0.05) and of mice which have two pregnancies decreased by 11% (P<0.05). Ovariectomy at the age of 2 months was followed by 32.7% increase in mean life span of mice. The inciden...

Pomegranate is known to contain estrogens (estradiol, estrone, and estriol) and show estrogenic activities in mice. In this study, we investigated whether pomegranate extract is effective on experimental menopausal syndrome in ovariectomized mice. Prolongation of the immobility time in forced swimming test, an index of depression, was measured 14 days after ovariectomy. The bone mineral density...

Objectives The role of isoflavones in pulmonary structure and function during menopause is not well studied. Moreover, the important role of estrogen in the physiological function of respiratory system has been revealed. Genistein, as an isoflavone, mimics estrogenic in diabetic and ovariectomized rats. Here, we hypothesized that genistein would reverse changes in the protein expression levels ...

We have previously demonstrated that altered exocrine pancreatic stimulus-secretion coupling is associated with ovariectomy and chronic estradiol administration. To elucidate possible mechanisms underlying those effects we examined the ability of chronic administration of different doses of estradiol to regulate the CCK signal transduction pathway in isolated rat pancreatic acini. Doses of estr...