119,942 research outputs found
Polycystic Ovary Syndrome: From Contraception to Hormone Replacement Therapy
No full textPolycystic ovary syndrome (PCOS) is a common disease based on a combination of various endocrine impairments. The use of hormonal treatments permits the aesthetic disturbances to be counteracted (acne, hirsutism, alopecia), but greater attention has to be given to insulin resistance, which may induce more severe diseases, such as diabetes. The use of oral contraceptives is helpful, but a lifestyle change is considered essential so as to improve the natural ability to resist disease affecting the circulation and metabolism. When the menopausal transition starts, greater attention is given to those PCOS patients who demonstrated insulin resistance during their fertile life. The use of hormone replacement therapy is often suggested as it has been proven to be beneficial
Amyloid-beta Induced Deregulation of Calcium Homeostasis in Glial Cells in an Innovative Model of Alzheimer’s Disease
No full textPathogenesis of PCOS: From Metabolic and Neuroendocrine Implications to the Choice of the Therapeutic Strategy
No full textPCOS is a quite frequent reproductive disease that affects 5–20% of the female population. Though specific diagnostic criteria have been established, probably they need an update according to the new insights recently ascertained, that is, insulin resistance (IR) and compensatory hyperinsulinemia. In addition, new specific insights have been demonstrated in animal models of PCOS that suggest a clear role of a neuroendocrinological impairment that might occur during prenatal life and/or after birth affecting the regular function of the reproductive axis. All these aspects suggest that PCOS might have a certain grade of epigenetic origins that might be implemented by familial predisposition to specific dismetabolic diseases such as diabetes. We will try to focus on these aspects to give an update on the putative therapeutical possibilities
Might DHEA be Considered a Beneficial Replacement Therapy in the Elderly ?
No full textDehydroepiandrosterone (DHEA) [prasterone] is typically secreted by the adrenal glands and its secretory rate changes throughout the human lifespan.When human development is completed and adulthood is reached, DHEA and DHEA sulphate (DHEAS) [PB-008] levels start to decline so that at 70–80 years of age, peak DHEAS concentrations are only 10–20% of those in young adults.This age-associated decrease has been termed ‘adrenopause’, and since many agerelated disturbances have been reported to begin with the decline of DHEA/DHEAS levels, this provides a potential opportunity for use of DHEA as replacementtherapy.For these reasons, use of DHEA as a replacement therapy in aging men and women has been proposed and this paper outlines the reported beneficial effects ofsuch treatment in humans. Many interesting results have been obtained in experimental animals suggesting that DHEA positively modulates most age-related disturbances. However, renewed interest in DHEA has arisen as a result of recentstudies suggesting that DHEA appears to be beneficial in hypoandrogenic men as well as in postmenopausal and aging women. Menopause is the event in awoman’s life that induces a dramatic change in the steroid milieu, and use of DHEA as ‘replacement treatment’ has been reported to restore both the androgenic and estrogenic environment and reduce most of the symptoms of this change.As menopause is the beginning of the biological transition of women towards senescence, it is of great interest to better understand how DHEA might help to solve and/or overcome the problems of this complex stage of life. In men withadrenal insufficiency and hypogonadism without androgen replacement, DHEA administration results in a significant increase in circulating androgens.Though most data are suggestive for use of DHEA as hormonal replacement treatment, more defined and specific clinical trials are needed to uncover all of the ‘secrets’ and features of this steroid before it can be used as a standard treatment.Furthermore, DHEA is perceived differently around the world, being considered only a ‘dietary supplement’ in the US, while in many European countries it isconsidered a ‘true hormone’ that has not been approved for use as a hormonal treatment by the European health authorities. This overview offers some points of view on use of DHEA as an experimental hormonal replacement therapy
Oral dehydroepiandrosterone restores ß-endorphin response to OGTT in early and late postmenopause
No full textß-endorphin is a neuropeptide involved in several brain functions: its plasma levels are higher in obese women and its release increases after oral glucose tolerance test (OGTT) in normal or obese women. The study included 46 healthy women and evaluated the effect of oral dehydroepiandrosterone [DHEA] (50 mg/day) in early postmenopausal women (50–55 years) both of normal weight (group A, n = 12, BMI = 22.1 ± 0.5) and overweight (group B, n = 12, BMI = 28.2 ± 0.5), and late postmenopausal women (60–65 years) both normal weight (group C, n = 11, BMI = 22.5 ± 0.6) and overweight (group D, n = 11, BMI = 27.9 ± 0.4) undergone OGTT, in order to investigate if DHEA could restore/modify the control of insulin and glucose secretion and ß-endorphin release in response to glucose load. The area under the curve (AUC) of OGTT evaluated plasma levels of different molecules. DHEA, DHEAS, and ß-endorphin plasma levels were lower in baseline conditions in older women than younger women. Considering the AUC of ß-endorphin response to OGTT, all groups showed a progressive significant increase after 3 and also after 6 months of treatment in comparison to baseline and 3 months of treatment
Contraception as prevention and therapy: sex steroids and the brain
No full textThe brain is one of the specific target tissues for sex steroid hormones. Estrogens, progestins and androgens are able to induce several effects in brain areas of the central nervous system (CNS), through the binding with specific receptors. Specific receptors for gonadal steroids have been identified in the amygdala, hippocampus, basal forebrain cortex, cerebellum, locus ceruleus, midbrain rafe nuclei, glial cells, pituitary gland, hypothalamus and central gray matter.At the hypothalamic level, the principal target for sex steroids is those neurons producing the pulsatile release of the gonadotropin releasing hormone (GnRH), localized in the mediobasal hypothalamus and the arcuate nucleus.The GnRH release depends on the complex and co-ordinated interrelationships among gonadal steroids, pituitary gonadotropins and neuroactive transmitters, such as the noradrenaline, dopamine, opioid peptides (β-endorphin), acetylcholine, serotonin, γ-aminobutyrric acid, corticotropin releasing hormone and neuropeptide Y.The interplay of these control mechanisms is governed by peripheral feedback signals; as well as the input from higher brain centers they may modify the GnRH secretion. The anterior pituitary lobe is the best known target tissue for endogenous or exogenous sex steroid hormones, because it is possible to detect luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels in blood, as the expression of the pituitary cells' activity. The synthesis and release of FSH and LH by the gonadotropic cells depend upon the peripheral control of gonadal hormones and the GnRH hypothalamic release. In summary, during a woman's reproductive life, the interaction between neurotransmitters, neuropeptides and gonadal hormones modulates the hypothalamo-pituitary-gonadal axis by acting selectively on the synthesis and release of GnRH and of pituitary gonadotropic hormones.The increased use of oral contraceptives in the last 30 years and, in general, of sex steroid hormone derivative therapies, has led to the study of the biochemical and metabolic properties of the different progestin molecules available in hormonal therapies by focusing attention on the interactions between estrogens and progestins in the modulation of the hypothalamo-pituitary-gonadal axis.The different kinds of estrogen and progestin molecules used in oral contraceptives inhibit the ovulatory process and may interfere with other sex steroid hormone receptors, thus exerting multiple effects in each target tissue
Oral dehydroepiandrosterone restores β-endorphin response to OGTT in early and late postmenopause
No full textβ-endorphin is a neuropeptide involved in several brain functions: its plasma levels are higher in obese women and its release increases after oral glucose tolerance test (OGTT) in normal or obese women. The study included 46 healthy women and evaluated the effect of oral dehydroepiandrosterone [DHEA] (50 mg/day) in early postmenopausal women (50–55 years) both of normal weight (group A, n = 12, BMI = 22.1 ± 0.5) and overweight (group B, n = 12, BMI = 28.2 ± 0.5), and late postmenopausal women (60–65 years) both normal weight (group C, n = 11, BMI = 22.5 ± 0.6) and overweight (group D, n = 11, BMI = 27.9 ± 0.4) undergone OGTT, in order to investigate if DHEA could restore/modify the control of insulin and glucose secretion and β-endorphin release in response to glucose load. The area under the curve (AUC) of OGTT evaluated plasma levels of different molecules. DHEA, DHEAS, and β-endorphin plasma levels were lower in baseline conditions in older women than younger women. Considering the AUC of β-endorphin response to OGTT, all groups showed a progressive significant increase after 3 and also after 6 months of treatment in comparison to baseline and 3 months of treatment
Specific concordance index defines the physiological lag between LH and progesterone in women during the midluteal phase of the menstrual cycle
No full textUsing a recently developed statistically based method for assessment of the degree of concordance, we evaluated the degree of specific concordance (SC) between luteinizing hormone (LH) and progesterone secretory patterns. Eight healthy women volunteered for this study, undergoing a 12-h pulsatility study, sampling every 10 min. LH and progesterone pulse frequencies were estimated with the program DETECT (9.75 +/- 1 and 11.5 +/- 0.9 pulses/12 h, respectively; mean +/- SEM). The temporal relationship between LH and progesterone secretions was evaluated with cross-correlation analysis and with the computation of the SC index. Cross-correlation showed concordance between LH and progesterone (p less than 0.05) at a range of lag between 0 and 40 min, while the SC index indicated that LH and progesterone pulses were significantly (p less than 0.05) and maximally correlated at 10-min lag. In conclusion, our data demonstrated that the specific concordance confirms the statistically significant concordance of LH and progesterone secretory events in women during the midluteal phase. In addition, the use of this new, objective, statistically based approach permits, compared to traditional cross-correlation analysis, a more precise definition of the physiological time lag for temporal coupling of secretory events between the two hormones
The duration of prolactin secretory bursts from the pituitary is independent from both prolactin and gonadal steroid plasma levels in women and in men
No full textThe intrinsic secretory characteristics of prolactin (PRL) have been investigated using newly developed algorhythms for instantaneous secretory rate (ISR) computation. PRL secretory rate, its intrinsic pulsatile characteristics and their possible dependance from gonadal steroids were investigated in five groups of subjects: a) 11 women during the follicular and luteal phase of the same menstrual cycle; b) 5 healthy postmenopausal women; c) 6 women affected by functional hyperprolactinemia; d) 5 normal men; e) 4 agonadal subjects before and during testosterone replacement therapy. All subjects underwent a 6 hours pulsatility study, from 08:00 to 14:00, sampling every 10 minutes. PRL plasma concentrations were determined using a RIA system and the presence of PRL secretory pulses was evaluated with program DETECT, both on plasma time series and after ISR computation. A distinct PRL episodic release was observed in all groups (follicular phase: 5.5 +/- 0.5, luteal phase: 6.5 +/- 0.6, postmenopause: 5 +/- 1, hyperprolactinemic women: 4.2 +/- 0.8, men: 4.8 +/- 0.4, agonadal before testosterone: 6 +/- 1, agonadal during testosterone administration: 5.3 +/- 0.3 peaks/6h), but mainly the computation of ISR allowed to demonstrate that the duration of the lactotropes secretory events was constant in all groups studied. PRL secretory bursts duration ranged between 23.1 +/- 1.8 and 25.4 +/- 2.5 minutes independently both on PRL or on sex steroid plasma levels. In conclusion, the present report shows that in different physiological conditions the intrinsic secretory bursts from lactotropes are constant in duration independently from the functional state, sex and the steroid hormone levels
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