Soy isoflavone effects on the adrenal glands of orchidectomized adult male rats: a comprehensive histological and hormonal study.

Genistein (G) and related soy phytoestrogens have been studied for potential usefulness in different chronic diseases, and may ameliorate signs of aging. They have a profound influence on the hypothalamo-pituitary-adrenal (HPA) axis. The present study utilized the rat model of mild andropause to thoroughly evaluate the effects of G and soy extract on the adrenal gland and related blood hormones.

Effects of Prenatal Dexamethasone on the Rat Pituitary Gland and Gonadotropic Cells in Female Offspring.

Glucocorticoids have a strong influence on growth and maturation of fetal organ systems, but overexposure to exogenous glucocorticoids may retard fetal growth and alter developmental processes in sensitive tissues. The aim of this study was to specifically determine whether prenatal exposure to dexamethasone (Dx) altered normal development and function of pituitary gonadotropic cells in neonatal, infant and peripubertal female offspring. On day 16 of pregnancy, rat dams received 1.

Mechanism of action of levonorgestrel emergency contraception.

There has been much debate regarding levonorgestrel emergency contraception's (LNG-EC's) method of action since 1999 when the Food and Drug Administration first approved its use. Proponents of LNG-EC have argued that they have moral certitude that LNG-EC works via a non-abortifacient mechanism of action, and claim that all the major scientific and medical data consistently support this hypothesis. However, newer medical data serve to undermine the consistency of the non-abortifacient hypothesis and instead support the hypothesis that preovulatory administration of LNG-EC has significant potential to work via abortion.

Age-dependent modulation of central ghrelin effects on food intake and lipid metabolism in rats.

Ghrelin is an endogenous peptide potentially useful in therapy of anorexia and other age-related metabolic disturbances. We evaluated the influence of age on the orexigenic and lipid metabolism-altering effects of ghrelin. Peripubertal, young, adult and middle-aged rats (1, 2, 7 and 12 months old, respectively) were treated with 5 daily intracerebroventricular injections of ghrelin (0.

Central effects of ghrelin on the adrenal cortex: a morphological and hormonal study.

Ghrelin, a growth hormone secretagogue that exerts an important role in appetite and weight regulation, participates in the activation of the hypothalamo-pituitary-adrenal (HPA) axis. Male Wistar rats (5/group) received daily for 5 days, via an ICV (intracerebroventricular) cannula, 5 microl phosphate buffered saline with or without 1 microg of rat ghrelin. Two hours after the last injection, blood and adrenal glands were collected from decapitated rats for blood hormone analyses and histologic and morphometric processing.

Consummatory behavior and metabolic indicators after central ghrelin injections in rats.

Ghrelin, an endogenous ligand for the growth-hormone-secretagogue receptor, is a 28-amino acid peptide with a post-translational acyl modification necessary for its activity. It has central nervous system actions that affect appetite, body mass and energy balance. An intracerebroventricular (ICV) injection protocol of sub-nanomolar doses of ghrelin, known to alter the morphology of ACTH and GH producing pituicytes and plasma levels of these hormones, was used to provide an overview of metabolic changes linked to energy metabolism.

Hydrogen peroxide induces lysosomal protease alterations in PC12 cells.

Alterations in lysosomal proteases have been implicated in many neurodegenerative diseases. The current study demonstrates a concentration-dependent decrease in PC12 cell viability and transient changes in cystatin C (CYSC), cathepsin B (CATB), cathepsin D (CATD) and caspase-3 following exposure to H2O2. Furthermore, activation of CATD occurred following exposure to H2O2 and cysteine protease suppression, while inhibition of CATD with pepstatin A significantly improved cell viability.

6-Hydroxydopamine induces cystatin C-mediated cysteine protease suppression and cathepsin D activation.

Alteration in the lysosomal system (LS) may represent a central mechanism in neurodegeneration. 6-Hydroxydopamine (6-OHDA) induces oxidative stress and cell death in catecholaminergic cells. The LS and caspases participate in apoptosis, although the mechanism(s) that is involved is not completely understood.

The effect of centrally administered ghrelin on pituitary ACTH cells and circulating ACTH and corticosterone in rats.

Ghrelin is a brain-gut peptide known for its growth hormone (GH)-releasing and appetite-inducing activities. This natural GH secretagogue (GHS) was originally purified from rat stomach, but it is expressed widely in different tissues where it may have endocrine and paracrine effects. The central effects of ghrelin on adrenocorticotropic hormone (ACTH) cells, ACTH release and subsequent corticosterone release from adrenal glands remains to be clarified.

Central effects of ghrelin on serum growth hormone and morphology of pituitary somatotropes in rats.

Ghrelin, an endogenous ligand for the growth hormone (GH) secretagogue receptor, was originally purified from rat stomach; subsequently, ghrelin neurons were found in the arcuate nuclei of rats. Central effects of the peptide on GH release, however, remain to be clarified. The aim of the present study was to determine the morphologic features of GH-producing pituicytes and serum GH concentration after central administration of ghrelin.

Oral contraceptive use as a risk factor for premenopausal breast cancer: a meta-analysis.

Objective: To perform a meta-analysis of case-control studies that addressed whether prior oral contraceptive (OC) use is associated with premenopausal breast cancer.

Methods: We searched the MEDLINE and PubMed databases and bibliography reviews to identify case-control studies of OCs and premenopausal breast cancer published in or after 1980. Search terms used included breast neoplasms, oral contraceptives, contraceptive agents, and case-control studies.

Somatostatin-14 alters the thymus size and relation among the thymocyte subpopulations in peripubertal rats.

It is well known that somatostatin exerts a wide range of effects in the body, and acts as an autocrine or paracrine factor in the thymus. However, it has not been investigated yet whether somatostatin alters the thymus size and relation among the thymocyte subpopulations in the peripubertal rats. For this purpose, the peripubertal AO male rats were cannulated intracerebroventriculary and treated with repeated, low doses of somatostatin-14 (experimental group) or saline (control group).

Somatostatin affects morphology and secretion of pituitary luteinizing hormone (LH) cells in male rats.

The somatostatin peptides (SRIH-14, SRIH-28) and their multiple receptors are generally associated with anti-proliferative and anti-secretory actions. This study compared, using standard morphometric measurements and terminal serum LH concentrations, effects of intracerebroventricular (icv) SRIH-14 and SRIH-28 in nanomolar amounts on immunohistochemically identified LH cells in pituitary glands of male rats. Rats received l microg/5 microl of SRIH-14 or SRIH-28 icv on days 1,3, and 5, whereas control rats received only icv saline.

Effects of centrally applied somatostatin on pituitary adrenocorticotropes in female rats.

Effects of intracerebroventricular (i.c.v.

Effects of ethacrynic acid on intraocular pressure of anesthetized rats.

Ethacrynic acid (ECA) lowers intraocular pressure (i.o.p.

Aqueous humor dynamics in anesthetized rats infused with intracameral apraclonidine.

We studied the acute effects of the ocular hypotensive drug, apraclonidine (AP), on intraocular pressure (IOP) and aqueous humor dynamics of anesthetized rats during infusion-induced ocular hypertension. Two infusions were made into the anterior chamber of the eye: one was constant at a rate of 0.05 microl/min, the other was cyclic, at a rate of 0.

Timolol effects on aqueous humor dynamics in eyes of anesthetized rats.

Anterior chambers of the eyes of male rats were cannulated under pentobarbital anesthesia for intracameral infusions of balanced salt solution (BSS) and intraocular pressure (IOP) recording. Blood pressure was recorded from a femoral artery. IOP was recorded during a 2-h intracameral infusion composed of a constant component (0.

Morphometric and functional changes of rat pituitary somatotropes and lactotropes after central administration of somatostatin.

This study examined effects of intracerebroventricularly (i.c.v.

Mechanisms for vasopressin effects on intraocular pressure in anesthetized rats.

Continuous intracameral infusions of a balanced salt solution (0.175 microliter min-1) have been reported to raise intraocular pressure (IOP) in anesthetized rats. Palm et al.

Excess coffee consumption in simulated complex work settings: detriment or facilitation of performance?

Twenty-four managers who normally consume between 400 and 1,000 mg of caffeine per day participated in all-day quasi-experimental simulations. In a crossover, doubleblind design, they made complex managerial decisions either on treatment with their typical daily dose of caffeine or on treatment with 400 mg of caffeine in excess of daily consumption. The effect of caffeine treatment on various validated performance indicators was investigated.