Search results for "Ovariectomy"
showing 10 items of 51 documents
Molecular mechanisms involved in the hormonal prevention of aging in the rat.
2008
Previous data from our group have provided support for the role of GH, melatonin and estrogens in the prevention of aging of several physiological parameters from bone, liver metabolism, vascular activity, the central nervous system (CNS), the immune system and the skin. In the present work data on the molecular mechanisms involved are presented. A total of 140 male and female rats have been submitted to different treatments over 10 weeks, between 22 and 24 months of age. Males have been treated with GH and melatonin. Females were divided in two groups: intact and castrated at 12 months of age. The first group was treated with GH and melatonin and the second with the two latter compounds an…
New antitrichomonal drug-like chemicals selected by bond (edge)-based TOMOCOMD-CARDD descriptors.
2008
Bond-based quadratic indices, new TOMOCOMD-CARDD molecular descriptors, and linear discriminant analysis (LDA) were used to discover novel lead trichomonacidals. The obtained LDA-based quantitative structure-activity relationships (QSAR) models, using nonstochastic and stochastic indices, were able to classify correctly 87.91% (87.50%) and 89.01% (84.38%) of the chemicals in training (test) sets, respectively. They showed large Matthews correlation coefficients of 0.75 (0.71) and 0.78 (0.65) for the training (test) sets, correspondingly. Later, both models were applied to the virtual screening of 21 chemicals to find new lead antitrichomonal agents. Predictions agreed with experimental resu…
Evidence that 3 alpha-hydroxy-5 alpha-pregnan-20-one is a physiologically relevant modulator of GABA-ergic neurotransmission.
1991
Abstract 3α-Hydroxy-5α-pregnan-20-one (HPO) is a progesterone metabolite which exhibits narcotic properties at high concentrations by interactions with the receptor for gamma-aminobutyric acid (GABA). The present investigation characterized low-dose effects of HPO on GABA A receptor binding, by determining the allosteric properties of HPO on the in vitro binding of 3 H-muscimol to membrane fractions from the cerebella of ovariectomized rats. A newly developed method for tissue preparation was used to wash out endogenous ligands interfering with the assay. HPO reduced the affinity of 3 H-muscimol to GABA A receptor sites by 52% and enhanced the number of accessible binding sites from 5.5±0.5…
Estrogenic effects of food wrap packaging xenoestrogens and flavonoids in female Wistar rats : a comparative study
2003
International audience; The objective of this study was to compare the estrogenicity of xenoestrogens found in food wrap packaging and phytoestrogen flavonoids. Uterotrophic and vaginal cornification assays were performed on immature and ovariectomized rats. Genistein, bisphenol F, and octylphenol were identified as estrogenic only in immature rats. Using vaginal cornification as a more specific estrogenic parameter, all tested compounds except tangeretin were active in immature rats. While apigenin and kaempferol appeared to have low estrogenic activity, they potentialized the uterotrophic effect of 17β-estradiol in immature rats. These data showed that (i) phytoestrogens like genistein ca…
Isoflavonoid-based bone-sparing treatments exert a low activity on reproductive organs and on hepatic metabolism of estradiol in ovariectomized rats
2007
International audience; The use of soy isoflavones is a potential alternative to hormone replacement therapy in post-menopausal bone-loss prevention. Nevertheless, phytoestrogens can target other organs and may disrupt cell proliferation, or could modify endogenous steroid hormone metabolism. These mechanisms could be linked to an increased risk of developing cancer. We therefore studied the possible side effects of such treatments in an experimental model of menopause. Forty adult female Wistar rats were ovariectomized and fed with a genistein-, daidzein- or equol-supplemented diet at bone-sparing levels (10 mg/kg BW/day) for 3 months. The estrogenic effects were assessed by histological a…
Laparotomic vs laparoscopic ovariectomy: comparing the two methods. The ovariectomy in the bitch in laparoscopic era
2015
BACKGROUND: The aim of the present work is to evaluate the effectiveness of the use of ultrasound scalpel during laparoscopic ovariectomy in the bitch. METHODS: Two groups of 10 subjects each, of different races and ages, were compared. In the first group, ovariectomy was performed laparoscopically, using harmonic scalpel to remove ovary. In the second group surgery was performed by means of classical laparotomy. RESULTS: Pre-operative time was similar in both groups. Total operative time, from incision to skin suture, showed significant difference between the two groups, being laparoscopy faster than laparotomy. Partial operative time for bilateral oophorectomy resulted lower using open te…
Trans- but not cis-resveratrol impairs angiotensin-II-mediated vascular inflammation through inhibition of NF-κB activation and peroxisome proliferat…
2010
Abstract Angiotensin II (Ang-II) displays inflammatory activity and is implicated in several cardiovascular disorders. This study evaluates the effect of cis- and trans (t)-resveratrol (RESV) in two in vivo models of vascular inflammation and identifies the cardioprotective mechanisms that underlie them. In vivo, Ang-II–induced arteriolar leukocyte adhesion was inhibited by 71% by t-RESV (2.1 mg/kg, i.v.), but was not affected by cis-RESV. Because estrogens influence the rennin-angiotensin system, chronic treatment with t-RESV (15 mg/kg/day, orally) inhibited ovariectomy-induced arteriolar leukocyte adhesion by 81%, partly through a reduction of cell adhesion molecule (CAM) expression and c…
Anti-atherogenic Effects of 17β-Estradiol
2013
Estrogens are secreted primarily by the ovaries and placenta, by the testes in men and also produced by peripheral steroidogenic conversion. The 3 major naturally occurring estrogens are: 17β-estradiol (E2), estrone and estriol, of which E2 is the predominant and most active. The actions of E2 are mediated by at least 3 different receptors - the classical ERs (ERα and ERβ) and G-protein coupled receptor 30 (GPR30). E2 signaling in cardiomyocytes involves ERα- and ERβ-independent pathways, and treatment with the E2 receptor antagonists (Selective Estrogen Receptor Modulators- SERMs), which are agonists of GPR30, inhibits cardiac cell growth. Effects of E2 in preventing endothelial dysfunctio…
Mitochondria from females exhibit higher antioxidant gene expression and lower oxidative damage than males
2003
We have investigated the differential mitochondrial oxidative stress between males and females to understand the molecular mechanisms enabling females to live longer than males. Mitochondria are a major source of free radicals in cells. Those from female rats generate half the amount of peroxides than those of males. This does not occur in ovariectomized animals. Estrogen replacement therapy prevents the effect of ovariectomy. Mitochondria from females have higher levels of reduced glutathione than those from males. Those from ovariectomized rats have similar levels to males, and estrogen therapy prevents the fall in glutathione levels that occurs in ovariectomized animals. Oxidative damage…
Actions of sex hormones on the brain
1992
1. The brain is a target for sex steroid hormones. As a result of sex hormone actions on the brain various behavioral changes are observed in animal and man. This paper gives a brief overview over the multiple central nervous functions that are under modulatory control of sexual hormones and describes the complex sex steroid actions on the brain by giving an example for "activating" and "organizing" effects of estrogens on noradrenergic neurons in the brain of rats. 2. Estradiol-17 beta induced sex specific alterations in the turnover of noradrenaline in the preoptic area and mediobasal hypothalamus showing "female" or "male" responses. 3. Neonatal manipulations of female rat pups by testos…