An in vivo model of glutamate excitotoxicity in which glutamate is applied to the cortex of rats through a microdialysis probe has been used to investigate the neuroprotective processes initiated by 17 beta-estradiol. Rats were pre-treated with 17 beta-estradiol i.v. before local application of glutamate. The experimental results showed that pre-treatment with 17 beta-estradiol significantly reduced the size of the glutamate-induced lesion. In the microdialysates, the peak of lactate observed immediately after glutamate application was significantly higher and longer lasting after 17 beta-estradiol pre-treatment. The level of extracellular glucose was markedly decreased concomitantly to the increase in lactate, but no difference could be observed with and without 17 beta-estradiol pre-treatment. These suggest a new neuroprotective mechanism of 17 beta-estradiol by activating glutamate-induced lactate production. This effect on lactate production and lesion reduction is estrogen receptor dependent and is abolished totally by estrogen antagonist tamoxifen. It was also demonstrated here that high lactate subserves estrogen neuroprotection during glutamate toxicity.
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http://dx.doi.org/10.1007/BF02888040 | DOI Listing |
Endocrine
December 2024
Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Health Sciences, Kartal Dr. Lutfi Kirdar City Hospital, Kartal, Istanbul, Turkey.
Objectives: The relationship between elevated ferritin levels and metabolic abnormalities in PCOS patients, and whether ferritin is a cause or a consequence, is still debated. This study aimed to evaluate the impacts of the fourth generation combined oral contraceptive containing ethinyl estradiol/drospirenone (EE 30 mcg/DRSP 3 mg), known for its favorable metabolic profile and lower side effect risk, on iron metabolism in PCOS patients, while also exploring the potential relationship between metabolic parameters and iron status.
Methods: The retrospective analysis was conducted on 81 women aged 18-45, diagnosed with PCOS according to the Rotterdam criteria and treated with EE/DRSP for six months.
J Endocrinol
November 2024
School of Life and Health Sciences, University of Roehampton, London, UK.
LEAP2, a liver-derived antagonist for the ghrelin receptor, GHSR1a, counteracts the effects of ghrelin on appetite and energy balance. Less is known about its impact on blood glucose-regulating hormones from pancreatic islets. Here, we investigate whether acyl-ghrelin (AG) and LEAP2 regulate islet hormone release in a cell-type- and sex-specific manner.
View Article and Find Full Text PDFFish Physiol Biochem
December 2024
Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València. Camino de Vera S/N, 46022, Valencia, Spain.
To induce sexual maturation in captivity, eels rely on hormonal treatments, but this process is costly and time-consuming. As an alternative, different types of conditioning, also referred as pre-treatment, have been assessed to ease hormonal treatment response. Recent studies have shown that migrating eels experience a wide range of temperatures, varying from 12 °C at night to as low as to 8 °C during the day.
View Article and Find Full Text PDFAntioxidants (Basel)
August 2024
Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410500, Israel.
Skin aging is associated with the increased production of mitochondrial reactive oxygen species (mtROS) due to mitochondrial dysfunction, and various phytonutrients and estrogens have been shown to improve skin health. Thus, the aim of the current study was to examine damage to dermal fibroblasts by chemically induced mitochondrial dysfunction and to study the mechanism of the protective effects of carotenoids, polyphenols, and estradiol. Rotenone, a Complex I inhibitor, caused mitochondrial dysfunction in human dermal fibroblasts, substantially reducing respiration and ATP levels, followed by increased mitochondrial and cytosolic ROS, which resulted in apoptotic cell death, an increased number of senescent cells, increased matrix metalloproteinase-1 (MMP1) secretion, and decreased collagen secretion.
View Article and Find Full Text PDFHum Reprod
September 2024
Reproductive Medicine, Clinique Mutualiste La Sagesse, Rennes, France.
Study Question: Does luteal estradiol (E2) pretreatment give a similar number of retrieved oocytes compared to no-pretreatment in advanced-aged women stimulated with corifollitropin alfa in an antagonist protocol?
Summary Answer: Programming antagonist cycles with luteal E2 gave similar number of retrieved oocytes compared to no-pretreatment in women aged 38-42 years.
What Is Known Already: Programming antagonist cycles with luteal E2 pretreatment is a valuable tool to organize the IVF procedure better and is safe without any known impact on cycle outcome. However, variable effects were observed on the number of retrieved oocytes depending on the treated population.
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