Publications by authors named "Natalia Ordyan"

Previous studies indicated that reduced androgen levels may contribute to both physical and cognitive disorders in men, including Alzheimer's disease. New drug candidates for Alzheimer's disease in patients with androgen deficiency should ideally be able to act not only on multiple brain targets but also to correct impaired endocrine functions in hypogonadal men with Alzheimer's disease. Ropren is one such candidate for the treatment of Alzheimer's disease in men with an imbalance of androgens.

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This study elucidated the potential antidepressant-like effect of prolonged Ropren® administration (8.6 mg/kg, orally, once daily for 28 days) using a β-amyloid (25-35) rat model of Alzheimer's disease following gonadectomy. The experimental model was created by intracerebroventricular injection of β-amyloid (25-35) into gonadectomized (GDX) rats and GDX rats with testosterone propionate (TP, 0.

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The present preclinical study was designed to examine the effects of prolonged Ropren® administration (8.6 mg/kg, orally, once daily, 28 days) in a β-amyloid (25-35) rat model of Alzheimer's disease following gonadectomy. The experimental model was created by intracerebroventricular injection of β-amyloid (25-35) into gonadectomized (GDX) rats and GDX rats with testosterone propionate (TP, 0.

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Corticosteroid hormones are important intrinsic factors that not only mediate the response to stress but also largely contribute to the main physiological processes. The biological actions of these steroids involve, first of all, the activation of specific receptors, namely mineralocorticoid (MR) and glucocorticoid (GR) receptors. These two receptor types govern a flexible and well-balanced mechanism that leads to the often opposing changes in the cell.

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The preconditioning (PC) by using mild intermittent hypobaric hypoxia (PC) increases a resistance of the brain to severe hypoxia/ischemia and various stresses. Recently, potent antidepressant-like effects of PC have been described in animal models of depression. In the present study, the impact of PC on the activity and feedback regulation of the hypothalamic-pituitary-adrenal axis (HPA) impaired in depression has been studied in the model of shock-induced depression in rats.

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The effects of preconditioning using mild repetitive hypobaric hypoxia (360 Torr for 2 h each of 3 days) have been studied in the learned helplessness model of depression in rats. Male Wistar rats displayed persistent depressive symptoms (depressive-like behaviour in open field, increased anxiety levels in elevated plus maze, ahedonia, elevated plasma glucocorticoids and impaired dexamethasone test) following the exposure to unpredictable and inescapable footshock in the learned helplessness paradigm. Antidepressant treatment (ludiomil, 5 mg/kg i.

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Circulating glucocorticoids, of which their concentration is largely under the control of the hypothalamic-pituitary adrenal (HPA) axis, acting through the glucocorticoid receptors (GR) regulate a large variety of pivotal functions of the organism such as growth, development, immune- and stress-response. The main mechanism of regulation of the HPA axis activity is via negative feedback at all levels of the HPA axis itself as well as at the extra-hypothalamic level, a central part of which is the hippocampus. During neonatal development, the HPA axis of rats undergoes a period of hyporesponsiveness (SHRP)-when most stress stimuli fail to induce stress-response.

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