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Neuroprotective effects of female sex steroids in cerebral ischemia. Directory of Open Access Journals Sweden. Full Text Available The central and peripheral nervous system are important targets of sex steroids. Sex Club female Guelph in lko sex affect the brain development and differentiation, and influence neuronal functions. Recent evidence emphasizes a striking sex -linked difference in brain damage after experimental stroke, as well as the efficacy of hormones in treating cerebral stroke injury.
Several different models of cerebral ischemia have been utilized for hormone neuroprotection studies, including transient or permanent middle cerebral artery occlusion, transient global ischemia, and transient forebrain ischemia. Extensive experimental studies have shown that female sex steroids such as progesterone and estradiol exert neuroprotective effects in the experimental models of stroke, although deleterious effects have also been reported.
Also, a ificance of numerous factors, including gender and age of experimental animals, localization of brain lesion, duration of ischemia and precise dose of steroids has been pointed out.
There are multiple potential mechanisms that might be invoked to explain the beneficial effects of female sex steroids in brain injury, involving neuroprotection, anti-inflammatory properties, effects on vasculature and altered transcriptional regulation. A several clinical trials on the effects of sex hormones to traumatic brain injury have been performed, suggesting that hormone therapy may represent a new therapeutic tool to combat certain diseases, such as traumatic brain injury.
Further basic science studies and randomized clinical trials are necessary to reveal a potential application of these molecules as a new therapeutic strategy. Full Text Available The brain is not only the target of steroid hormones but also is able to locally synthesize steroids de novo. Evidence of the local production of steroids in the brain has been accumulating in various vertebrates, including teleost fish, amphibia, birds, rodents, non-human primates, and humans. In this review, we mainly focus on the local production of sex steroids in the hippocampal neurons of adult rodents rats and mice, a center for learning and memory.
From the data of the hippocampus of adult male rats, hippocampal principal neurons [pyramidal cells in CA1—CA3 and granule cells in dentate gyrus DG] have a complete system for biosynthesis of sex steroids. Next, we review the steroid synthesis in the hippocampus of female rats, since knowledge had been biased toward the data from males. Recently, we clarified that the levels of hippocampal steroids fluctuate in adult female rats across the estrous cycle. Accurate determination of hippocampal steroids at each stage of the estrous cycle is of importance for providing the for the fluctuation of female hippocampal functions, including spine density, long-term potentiation LTP and long-term depression LTD, and learning and memory.
These functional fluctuations in female had been attributed to the level of circulation-derived steroids. Finally, we introduce the direct evidence of the role of hippocampus-synthesized steroids in hippocampal function including neurogenesis, LTP, and memory consolidation.
Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids. Full Text Available Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase SOD, catalase CAT, and glutathione peroxidase GSH-Px were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and femaleswe also examined the regulation of these enzyme activities in macrophages by sex steroids.
GSH-Px activity did not differ between male and female macrophages. Castration and testosterone administration did not ificantly modify the activities of the antioxidant enzymes in male Club female Guelph in lko sex. This latter change was fully reversed by estrogen Club female Guelph in lko sex, whereas progesterone had a smaller effect. These led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.
Neuroprotection of Sex Steroids. Sex steroids are essential for reproduction and development in animals and humans, and sex steroids also play an important role in neuroprotection following brain injury. New data indicate that sex -specific responses to brain injury occur at the cellular and molecular levels.
This review summarizes the current understanding of neuroprotection by sex steroidsparticularly estrogen, androgen, and progesterone, based on both in vitro and in vivo studies.
Better understanding of the role of sex steroids under physiological and pathological conditions will help us to develop novel effective therapeutic strategies for brain injury. Comparing sex steroid levels during the annual cycles of rainbow trout Oncorhynchus mykiss diploid female XX and triploid female XXX genotypic sex. In this group, E2 concentrations peaked in November No ificant differences in hormone ranges related to egg output ability were observed.
Finally, sex steroid concentrations were low in the triploid female XXX fish compared to the female XX population. Nevertheless, maximum T The female triploid fish produced the lowest steroid hormone levels, such that these would be the most suitable for human consumption. Yet relatively few investigators who work with male subjects consider the effects of these hormones on learning and memory.
This review describes…. Morphology, sex steroid level and gene expression analysis in gonadal sex reversal of triploid female XXX rainbow trout Oncorhynchus mykiss. In non-mammalian vertebrates, estrogens and expressions of cyp19a1 and foxl2 play critical roles Club female Guelph in lko sex maintaining ovary differentiation Club female Guelph in lko sex development, while dmrt1 and sox9 are male-specific genes in testicular differentiation and are highly conserved.
Our demonstrated that the development of triploid female gon in rainbow trout went through arrested development, oocytes dedifferentiation, ovary reconstruction and sex reversal finally. During early gonadal development days post-fertilizationthe expressions of foxl2 and cyp19a1 increased linearly, while expressions of dmrt1 and sox9 were extremely suppressed, and E2 level was higher, while T level was lower. During the mid-to-late period of triploid female gonadal development days post-fertilizationthe expressions of dmrt1 and sox9 remained high and were very close to the quantity of diploid male genes, and T levels were even reaching diploid male plasma concentrations, while expressions of cyp19a1 and foxl2 were decreased, leading to decrease in E2 level.
We realized that the development model of rainbow trout triploid female gon was extremely rare, and the regulatory mechanism was very special. Genes involved in gonadal development and endogenous estrogens are pivotal factors in fish natural sex reversal. Sex steroids and neurogenesis. The brain has long been known as a dimorphic organ and as a target of sex steroids.
It is also a site for their synthesis. Sex steroids in numerous ways can modify cerebral physiology, and along with many processes adult neurogenesis is also modulated by sex steroids. This review will focus on the effects of the main steroidsestrogens, androgens and progestogens, and unveil some aspects of their partly disclosed mechanisms of actions. Gonadal steroids act on different steps of neurogenesis: cell proliferation seems to be increased by estrogens only, while androgens and progestogens favor neuronal renewal by increasing cell survival; differentiation is a common target.
Aging is characterized by a cognitive deficiency, paralleled by a decrease in the rate of neuronal renewal and in the levels of circulating gonadal hormones. Therefore, the effects of gonadal hormones on the aging brain are important to consider. The review will also be expanded to related molecules which are agonists to the nuclear receptors.
Sex steroids can modify adult neuronal renewal and the extensive knowledge of their actions on neurogenesis is essential, as it can be a leading pathway to therapeutic perspectives. All rights reserved. Birds can manipulate the offspring sex ratio under natural and experimental conditions. Various factors related to the avian mother, as well as her eggs, have been reported to be linked with the sex determination process.
These factors appear to affect the chance of laying a male or female egg. Sex steroid hormones during the ovarian cycle of an all- femaleparthenogenetic lizard and their correlation with pseudosexual behavior. Cnemidophorus uniparens is a unisexual lizard that reproduces by parthenogenesis. Individuals of this species display male-like and female -like copulatory behaviors during different phases of the ovarian cycle suggesting that these pseudocopulatory behaviors are hormonally activated.
To learn more about both the endocrinology of parthenogenesis and the possible hormonal activation of male-like copulatory behavior in female individuals, we 1 characterized changes in plasma levels of the sex steroid hormones progesterone, 5 alpha-dihydrotestosterone, testosterone, and 17 beta-estradiol during the ovarian cycle in both free-living and captive individuals, and 2 measured sex steroid hormones in plasma collected from captive individuals immediately after they expressed male-like or female -like copulatory behavior.
In general, the pattern of secretion of ovarian hormones in C. Estradiol is elevated only during the preovulatory phase, whereas progesterone increases slightly during vitellogenesis and then increases dramatically following ovulation. Circulating levels of androgen are very low and are generally below the sensitivity of our radioimmunoassay at all stages of the ovarian cycle.
The hormonal correlates of female -like copulatory behavior suggest that, as in other vertebrates, female receptivity is activated by a synergism of estradiol and progesterone. There is no evidence that the hormonal cycle has been altered to produce elevated levels of androgens during the phase Club female Guelph in lko sex the cycle when male-like behavior is expressed.
Rather it seems more likely that the central nervous system has evolved a novel response to a typical pattern of ovarian steroid hormone secretion. At present, the best hormonal correlate of male-like behavior is that changes in plasma levels of progesterone closely parallel changes in probability of expressing male-like behavior. Sex steroid hormones matter for learning and memory: estrogenic regulation of hippocampal function in male and female rodents. This review describes the effects of E2 on hippocampal spinogenesis, neurogenesis, physiology, and memory, with particular attention paid to the effects of E2 in male rodents.
The estrogen receptors, cell-aling pathways, and epigenetic processes necessary for E2 to enhance memory in female rodents are also discussed in detail. Finally, practical considerations for working with female rodents are Club female Guelph in lko sex for those investigators thinking of adding females to their experimental des.
Full Text Available AbstractObjective sGastric ulceration is induced by various forms of stress like surgery, ischemia and trauma. The female sex has more resistance to stress and the gastrointestinal lesions happen fewer than male sex. The purpose of this study was to evaluate the role of estradiol and progesterone on the gastric acid and pepsin levels following traumatic brain injury TBI induction. The acid content and pepsin levels of each gastric washout sample were measured 5 days after the TBI induction. In vivo effects of the sex steroids estrogen and progesterone on 3 H-leucine uptake by the brain of mature ovariectomized mice were examined.
Animals were divided into three groups: group 1, consisting of control animals treated with sesame oil, group 2, animals treated with estrogen, and group 3, animals first treated with estrogen and then with progesterone. Each group was given a single i.
Intensity of the uptake of radiolabeled leucine was measured by counting the of reduced silver grains over cells in various brain regions using an autoradiographic technique. Group 1 showed a relatively high uptake in the supraoptic nucleus, paraventricular nucleus PV and ventromedial nucleus VM when compared with that in the remaining hypothalamic nuclei examined. Group 2 showed a ificant enhancement of the uptake in all hypothalamic regions except the preoptic periventricular nucleus PPV when compared with that in group 1.
Group 3 showed enhancement of the uptake in all hypothalamic nuclei when compared with that in group 1. However, only the PV, PPV, VM and periventricular arcuate nucleus revealed a ificantly higher uptake than the respective nuclei in group 2.
The remaining nuclei showed no change in uptake. Uptake by cells in the ependymal cells and cerebral cortex remained unchanged after hormonal treatment. The present suggest that in female mice estrogen and estrogen plus progesterone stimulate protein synthesis in most of the Club female Guelph in lko sex nuclei and that the progesterone effect on protein synthesis is greatly influenced by estrogen-priming. Sex steroid levels across the reproductive cycle of female leopard geckos, Eublepharis macularius, from different incubation temperatures.
Incubation temperature during embryonic development determines gonadal sex in many reptiles, including the leopard gecko Eublepharis macularius. In this study, we examined the hormonal and behavioral changes that occur during the reproductive cycle of female leopard geckos from four i. Controlling for reproductive status, plasma levels of dihydrotestosterone DHTtestosterone Tand progesterone P varied with incubation temperature but estradiol beta E2 levels did not.
Controlling for the effects of incubation temperature, DHT and T levels were low when females were previtellogenic, increased slightly during early vitellogenesis, increased dramatically during late vitellogenesis i.
In contrast, E2 levels increased gradually from the previtellogenic stage to the early vitellogenic stage, peaked during late vitellogenesis, and decreased to previtellogenic levels after ovulation. Levels of P increased from the previtellogenic stage to the early vitellogenic stage, remained elevated during late vitellogenesis, and then decreased after ovulation.
Incubation temperature did not influence receptivity. Overall, these data show that hormone levels and behavior change coordinately during the reproductive cycle. Although incubation temperature has persistent effects on endocrine physiology in adult female leopard geckos, these effects are modest compared to hormonal changes across the reproductive cycle. The effects of female sex steroids on the development of autoimmune thyroiditis in thymectomized and irradiated rats. Pre-pubertal ovariectomy further augmented susceptibility.
Administration of oestrogen or progesterone to groups of 4 weeks old ovariectomized Tx-X animals over a period of 15 weeks ificantly altered induction of this condition. Oestrogen administered by a single implantation had a suppressive effect on the development of autoimmunity in ovariectomized Tx-X females. Oestrogen given by either of these procedures also reduced the incidence of thyroiditis and autoantibody induction in orchidectomized male Tx-X rats.
It is concluded that the differential susceptibility to the induction of autoimmunity by thymectomy and irradiation is the direct consequence of sex hormonal influences. The higher incidence of the disease in the female would appear to be determined by the balance between the activity of oestrogen and progesterone which would further appear to have antagonistic influences in Club female Guelph in lko sex particular situation.
Sex steroidsimmune system, and parasitic infections: facts and hypotheses. It has been widely reported that the incidence and the severity of natural parasitic infections are different between males and females of several species, including humans. This sexual dimorphism involves a distinct exposure of males and females to various parasite infective stages, differential effects of sex steroids on immune cells, and direct effects of these steroids on parasites, among others.
Typically, for a large of parasitic diseases, the prevalence and intensity is higher in males than females ; however, in several parasitic infections, males are more resistant than females. In the present work, we review the effects of sex hormones on immunity to protozoa and helminth parasites, which are the causal agents of several diseases in humans, and discuss the most recent research related to the role of sex steroids in the complex host-parasite relationship.
Full Text Available Dysregulation of uterine fluid environment could impair successful reproduction and this could be due to the effect of environmental estrogens.
Therefore, in this study, effect of quercetin, an environmental estrogen on uterine fluid and electrolytes concentrations were investigated under sex-steroid influence. Following sacrifice, uteri were harvested and levels of the proteins of interest were identified by Western blotting and Realtime PCR. Distribution of these proteins in the uterus was observed by immunofluorescence. Quercetin-induced changes in the uterine fluid secretion rate and. Female Sex Tourism. This project has positioned itself as a postcolonial critique, arguing that female sex tourism is a form of neocolonialism.
The pClub female Guelph in lko sex
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File - Franklin, Ursala, at Women in Science Conference, University of Guelph