29 research outputs found
Influence of endogenous and exogenous sex hormones on plasma brain-derived neurotrophic factor
No full textBACKGROUND: Brain-derived neurotrophic factor (BDNF) is a mediator of neuronal plasticity and influences learning, memory and cognitive behaviour. The aim of this study is to assess plasma BDNF variations according to hormonal status. METHODS: A total of 60 subjects were included: 20 fertile ovulatory women, 15 amenorrhoeic women and 25 postmenopausal women. Blood samples were collected after overnight fasting. For 5 out of the 20 fertile women, samples were collected every 2 days throughout the whole menstrual cycle. Following basal evaluation, 10 out of 25 postmenopausal women were administered a hormone replacement therapy (HRT) and reevaluated after 6 months of treatment. Plasma BDNF concentrations were measured by enzyme-linked immunosorbent assay. In fertile women, estradiol (E2), progesterone and gonadotrophins were also assessed. RESULTS: In fertile women, luteal phase levels of plasma BDNF were significantly higher than follicular phase levels (P < 0.001). BDNF increased from early follicular phase up to Day 14 of the cycle, reaching a pre-ovulatory peak, similar to E2. A second rise took place during mid-luteal phase, with a peak on Day 24. Amenorrhoeic subjects, as well as postmenopausal women, showed significantly lower plasma BDNF levels compared with fertile females (P < 0.001). BDNF was positively correlated with E 2 and progesterone and negatively correlated with menopausal age. HRT restored BDNF levels to those present in fertile women during the follicular phase. CONCLUSIONS: Plasma BDNF levels are influenced by hormonal status. Modifications in BDNF circulating levels during the menstrual cycle suggest a potential role for gonadal sex hormones (E2 and progesterone) in regulating neurotrophin expression. © The Author 2007. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved
Neuroendocrine effects of different estradiol-progestin regimens in postmenopausal women
No full textOBJECTIVE:
New regimens and routes of administration of hormonal replacement therapy (HRT) in climateric women are becoming available. Since there is no information on the neuroendocrine effects of sequential combined treatment with 17 beta-estradiol and a progestin, the present study evaluated the neuroendocrine, clinical vasomotor and psychological changes before and after different sequential combined HRT regimens (17 beta-estradiol plus nomegestrol acetate, or cyproterone acetate, or vaginal progesterone). Vasomotor and behavioral effects were evaluated by using the Kupperman score, while changes in plasma endorphin (beta-END) levels were used as marker of neuroendocrine effects.
METHODS:
Postmenopausal women (n = 30) were randomly divided into three groups (ten women for each group); all women received continuous 17 beta-estradiol (50 mg, transdermal) and each group was sequentially treated with different progestins for 12 days/month: group A, cyproterone acetate (5 mg p.o.); group B, nomegestrol acetate (5 mg p.o.); and group C, progesterone (100 mg, vaginal cream). A group of healthy fertile women (n = 8) served as control. Before and after 6 months of HRT, postmenopausal women underwent an evaluation of subjective Kupperman score and two neuroendocrine tests: (a) naloxone (4 mg i.v.) and (b) clonidine (1.25 mg i.v.). Plasma beta-END levels were measured before and at 15, 30, 45, 60 and 90 min after drug injection. Control women were studied by administering the two neuroendocrine tests only once.
RESULTS:
Postmenopausal women before HRT showed a pathological Kupperman and no changes of plasma beta-END levels in response to the clonidine and naloxone tests score. On the contrary the increase was significant in healthy women. In each of the three groups of treated women both naloxone and clonidine tests induced a significant increase in plasma beta-END levels (P < 0.01). After 6 months of HRT, an improvement of vasomotor and psychological symptoms was shown by a decrease of Kupperman score.
CONCLUSIONS:
The present study indicates that sequential treatment with transdermal 17 beta-estradiol and progestin, no matter which progestin was used, restores the beta-END release, improves vasomotor and psychological symptoms
Melatonin treatment delays reproductive aging of female rat via the opiatergic system
No full textIn female rat age-related reproductive decline is accompanied by progressive impairment of the neuroendocrine mechanisms that regulate LH secretion. The biosynthetic activity of the pineal gland is markedly depressed and the nocturnal secretion of melatonin decreases significantly. The aim of the present study was to evaluate whether the nocturnal administration of melatonin via the drinking water (0.4 micrograms/ml) throughout the course of aging from 14 to 24 months of age could (1) influence the age-related changes that occur in basal serum levels of LH and in the LH response to GnRH or to naloxone stimulation at 16, 18 and 20 months of age, and (2) delay the onset of the postreproductive constant estrous-anovulatory state as evaluated by the daily recording of vaginal smears and by occurrence of polyfollicular ovaries at 24 months of age. Our results demonstrate that melatonin replacement delays the increase in LH serum levels and the decrease in LH response to GnRH that occur in 18-month-old control animals. Furthermore, they show that melatonin treatment prevents the loss of LH response to naloxone manifested in control rats between 16 and 20 months of age. Melatonin also appears to prevent the progressive increase in the monthly occurrence of estrus phases as well as to decrease the number of rats with polyfollicular ovaries at 24 months of age in comparison to control animals. These results suggest that the age-related decrease in circulating melatonin during the night may contribute to the reproductive decline of aging, and that this effect may involve the central opioid system
Calcineurin controls the expression of numerous genes in cerebellar granule cells
No full textThe Ca(2+)/calmodulin-dependent phosphatase calcineurin plays a crucial role in gene expression in different cell types such as T-lymphocytes, cardiac myocytes, and smooth muscle cells. A possible role for calcineurin in gene expression was recently found in neurons, where calcineurin regulates the expression of several genes involved in Ca(2+) homeostasis. To detect additional genes regulated in a calcineurin-dependent way in neurons we analysed gene expression profiles of cerebellar granule cells cultured in depolarising conditions in the presence or absence of the calcineurin inhibitory agents FK506 and CsA. Using oligonucleotide arrays we identified 34 genes that are differentially expressed between the samples and confirmed the calcineurin-dependent regulation of some of these genes by RT-PCR. Therefore, our results, which are likely not to be comprehensive, suggest that calcineurin plays a fundamental role in neuronal gene expression by either activating or repressing the expression of genes such as receptors, transcription factors, and signalling molecules
Effects of hormone replacement therapy on plasma viscosity and Doppler variations in postmenopausal non-smokers and heavy smokers
No full textObjectives. To evaluate the effects of transdermal hormone replacement therapy (HRT) on some biological cardiovascular risk factors, specifically thromboxane B-2 level and plasma viscosity. Furthermore, we investigated Doppler flow modifications at the level of the uterine, internal carotid, ophthalmic and bladder wall arteries, and evaluated whether there were significant differences, in the examined parameters, between postmenopausal women who were non-smokers and heavy smokers. Methods. Forty-three postmenopausal women (age 53.6 +/- 3.3 years, mean +/- standard deviation) participated in the study and were divided into two groups (Group I: n = 21, normal controls; and Group II: n = 22, heavy smokers). Patients were treated with continuous estradiol transdermal supplementation and 12-day courses of medroxyprogesterone acetate every 2 months. They were studied at baseline and after 6 months (in the estrogen-only phase of the cycle). Results. Results showed a beneficial effect of hormone substitution after 6 months of therapy. Plasma viscosity decreased significantly after 6 months of therapy both in non-smokers and heavy smokers (-18% and -14%, respectively). Plasma levels of thromboxane 132, which were similar at baseline, underwent a dramatic reduction in both Group I and Group II (-93% and -88%, respectively). Doppler assessment of pulsatility index at the level of the uterine, internal carotid, ophthalmic and bladder wall arteries showed a significant reduction in vascular impedance at the end of treatment in both groups. However, the treatment was significantly less beneficial, in terms of the analyzed factors, in heavy smokers. Conclusions. Cigarette smoking represents a cardiovascular risk factor that can only partially be modified by the administration of transdermal HRT
Chronic lisuride treatment decrease ACTH but not 3-EP and β-LPH plasma levels in children Auteur(s) / Author(s)
No full textChronic lisuride treatment decrease ACTH but not 3-EP and β-LPH plasma levels in childre
Female precocious puberty, obesity and polycystic-like ovaries
No full textObjective To evaluate the characteristics of obese girls with gonadotropin releasing hormone-dependent precocious puberty with and without polycystic-like ovaries. Methods Forty-seven overweight (> 75(th) centile of the Italian reference data) girls with a diagnosis of isosexual precocious puberty underwent auxological analysis, hormonal assay and utero-ovarian sonographic and Doppler evaluation. On the basis of sonography the patients were subdivided into two groups, girls presenting normal ovaries (Group 1; n = 31) and those with polycystic-like ovaries (Group II; n = 16). Results The mean body weight was significantly higher (P = 0.003) in Group II than it was in Group I. In addition, the patients with polycystic-like ovaries fell within our definition of superobese (>= 97(th) centile of the Italian reference data) in 44% of cases. The uterine and ovarian volumes were significantly greater in Group II compared with Group I patients. The Doppler evaluation showed intraparenchymal ovarian vascularization and low downstream impedance to flow in all patients in Group II. Conclusions Girls with precocious puberty and polycystic ovaries, compared with those without polycystic ovaries, have a higher incidence of body weight exceeding the 85(th) centile of the Italian reference data (obesity). Copyrigh
