Search results for "Estrogen"
showing 10 items of 530 documents
Studies on effects of tamoxifen (ICI 46474) on agonistic encounters between pairs of intact mice.
1988
The anti-estrogen tamoxifen (Tam), which has been shown to dramatically suppress offensive behavior in male rats without markedly influencing other aspects of the social encounter, was tested for its effectiveness in mice. TO strain albino mice were given control injections or 50 or 100 micrograms of Tam for 4 or 8 days. Subsequently, mice were tested in pairs (for a particular dose and treatment duration) in which both animals received Tam, one animal received Tam and one saline, or both animals received saline control injections. Ten-minute videotaped encounters were analyzed in terms of total times allocated to nonsocial investigation, social investigation, offense, defense, sexual activ…
Expression pattern of estroprogestinic receptors in sinonasal inverted papilloma
2017
// Agostino Serra 1 , Rosario Caltabiano 2 , Giacomo Spinato 3 , Salvatore Gallina 4 , Salvatore Caruso 5 , Venerando Rapisarda 6 , Paola Di Mauro 1 , Veronica Castro 1 , Angelo Conti 1 , Luisa Licciardello 1 , Luigi Maiolino 1 , Salvatore Lanzafame 2 , Salvatore Cocuzza 1 1 Department of Medical and Surgical Sciences and Advanced Technologies “G. Ingrassia”, ENT Section, University of Catania, Catania, Italy 2 Department of Medical and Surgical Sciences and Advanced Technologies “G. Ingrassia”, Section of Anatomic Pathology, University of Catania, Catania, Italy 3 ENT Department, Rovigo Provincial Hospital, Rovigo, Italy 4 Department of Experimental Biomedicine and Clinical Neurosciences, …
Steroid hormone receptors in human melanoma.
1981
Human melanomas were investigated for the presence of high-affinity estrogen-, gestagen-, and glucocorticoid-binding proteins. A statistically significant difference was found for mean estrogen receptor (ER) concentrations in melanomas of male versus female origin: female origin 37.6 (0-107) fmol/mg protein, male origin 3.9 (0-8.3) fmol/mg protein. No significant difference between sexes was found for gestragen receptors: 41.5 (0-194) fmol/mg protein for melanomas of female origin versus 99 (0-362) fmol/mg protein for male. Sucrose density gradient analyses revealed specific binding for both receptor types in the 4-5 S region as well as in the 8 S region. The binding affinities were in the …
Ethopharmacological studies on the effects of antihormones on rodent agonistic behavior with especial emphasis on progesterone.
1991
The effects of a range of antiandrogens and antiestrogens on conflict behaviors in laboratory rats and mice are reassessed in the light of recent studies applying ethophamacological analyses (recording the full spectrum of behaviors) to such investigations. It is argued that any antihostility properties of the antiandrogen cyproterone acetate are largely a consequence of indirect actions on odor communication, whereas antiestrogens (e.g., tamoxifen and CI 680) seem to have more fundamental motivational effects in addition to communicatory actions. A detailed example of the approach is provided in which progesterone (which can be antiandrogenic) is given to rats paired in different ways. The…
Dietary phytoestrogens improve stroke outcome after transient focal cerebral ischemia in rats.
2006
As phytoestrogens are postulated as being neuroprotectants, we assessed the hypothesis that dietary isoflavone-type phytoestrogens are neuroprotective against ischemic stroke. Transient focal cerebral ischemia (90 min) was induced by middle cerebral artery occlusion (MCAO) following the intraluminal thread technique, both in rats fed with soy-based diet and in rats fed with isoflavone-free diet. Cerebro-cortical laser-Doppler flow (cortical perfusion, CP), arterial blood pressure, core temperature, PaO2, PaCO2, pH and glycemia were measured before, during and after MCAO. Neurological examination and infarct volume measurements were carried out 3 days after the ischemic insult. Dietary isofl…
The Potential of Antiestrogens as Centrally-Acting Antihostility Agents: Recent Animal Data
1988
Recent studies suggest that motivations for certain forms of masculine behavior including social aggression are mediated by central estrogen receptors. Two studies using antiestrogens in rodent species were performed. Intact male LH rats were given Tamoxifen or vehicle for 4 or 8 days. The three possible pairings were videotaped for 60 min. Intact male OF1 mice were given CI-680 or vehicle over 25 days. Similar pairings were carried out but some CI-680 or vehicle animals were paired with anosmic opponents. Encounters were videotaped for 10 min. In both experiments evidence was obtained that the antiestrogen markedly reduced time allocated to offense. Any variations in defense were a consequ…
Acute relaxant effects of 17-beta-estradiol through non-genomic mechanisms in rabbit carotid artery.
2002
Estrogens could play a cardiovascular protective role not only by means of systemic effects but also by means of direct effects on vascular structure and function. We have studied the acute effects and mechanisms of action of 17-beta-estradiol on vascular tone of rabbit isolated carotid artery. 17-Beta-estradiol (10, 30, and 100 microM) elicited concentration-dependent relaxation of 50 mM KCl-induced active tone in male and female rabbit carotid artery. The stereoisomer 17-alpha-estradiol showed lesser relaxant effects in male rabbits. Endothelium removal did not modify relaxation induced by 17-beta-estradiol. The NO synthase inhibitor L-NAME (100 microM) only reduced significantly relaxati…
Pharmacological profile of phytoestrogens in cerebral vessels: in vitro study with rabbit basilar artery.
2003
As a previous step to consider their use in the pharmacology for stroke, we investigated the effects of four phytoestrogens (i.e. genistein, daidzein, zearalanone and biochanin A) on cerebral vessels. Cerebral vascular responses were analyzed by conventional recording of isometric tension in rabbit basilar artery segments kept in organ bath under standard conditions. The four phytoestrogens elicited concentration-dependent relaxant responses of different potency in basilar artery segments previously contracted with either 5x10(-2) M KCl or 10(-4) M UTP. Neither endothelium removal, 10(-4) M N(omega)-nitro-L-arginine methyl ester (L-NAME, nitric oxide (NO) synthase inhibitor), 10(-5) M1 H-[1…
Estradiol masculinizes the posteromedial cortical nucleus of the amygdala in the rat
2000
It has been demonstrated that the posteromedial cortical amygdaloid nucleus (PMCo), is sexually dimorphic. It is shown (Experiment 1) that male orchidectomy on the day of birth (D1) decreases the volume and number of neurons of the PMCo, while a single injection of propionate testosterone to the female on D1 masculinizes the PMCo in this gender. Since male gonadectomy on D1 (Experiment 2) is counteracted by a single injection of estradiol benzoate in males it has been suggested that the masculinization of the PMCo is due to the aromatization of testosterone to estradiol in this structure. These findings support the hypothesis that the development of sex differences in structures that belong…
Glycogen synthase kinase 3β links neuroprotection by 17β-estradiol to key Alzheimer processes
2004
Estrogen exerts many of its receptor-mediated neuroprotective functions through the activation of various intracellular signal transduction pathways including the mitogen activating protein kinase (MAPK), phospho inositol-3 kinase and protein kinase C pathways. Here we have used a hippocampal slice culture model of kainic acid-induced neurotoxic cell death to show that estrogen can protect against oxidative cell death. We have previously shown that MAPK and glycogen synthase kinase-3beta (GSK-3beta) are involved in the cell death/cell survival induced by kainic acid. In this model and other cellular and in vivo models we have shown that estrogen can also cause the phosphorylation and hence …