Alessandra Cubeddu

Daily variation of brain-derived neurotrophic factor and cortisol in women with normal menstrual cycles, undergoing oral contraception and in postmenopause

BACKGROUND Plasma brain-derived neurotrophic factor (BDNF) levels are associated with the hormonal status of women. Moreover, the suprachiasmatic nucleus appears to be implicated in the modulation of BDNF central levels. We aimed to investigate whether BDNF circadian rhythms exist in women and if there is a relationship with cortisol circadian rhythmicity. Moreover, we aimed to establish whether the hormonal status influences BDNF diurnal variations. METHODS A total of 30 women were studied: 10 fertile ovulatory women, 10 women undergoing oral contraceptive (OC) therapy and 10 post-menopausal women. Basal BDNF and estradiol levels were assayed in blood samples collected after overnight fasting at regular intervals (08:00, 12:00, 16:00, 20:00, 24:00). BDNF and cortisol levels were measured in samples collected during the follicular and luteal phases in ovulatory women and once a month in OC and post-menopausal women. RESULTS Luteal BDNF levels were significantly higher than follicular levels in fertile women (P < 0.001). In OC women, BDNF levels were similar to the follicular BDNF levels, whereas in post-menopausal women, they were significantly lower (P < 0.001). BDNF showed a diurnal rhythm in the follicular phase and in women undergoing OC, although the diurnal rhythm was blunted in the luteal phase. In post-menopausal women, BDNF and cortisol levels significantly decreased during the day. CONCLUSIONS BDNF has a diurnal variation in women that is somewhat analogous to cortisol variation; however, the amplitude of the variation in BDNF levels appears to be influenced by ovarian function. Interactions between BDNF, the hypothalamus-pituitary-adrenal axis and sex steroids might play a critical role in the human homeostasis and adaptation.

Brain-derived neurotrophic factor plasma variation during the different phases of the menstrual cycle in women with premenstrual syndrome

Premenstrual syndrome (PMS) is characterized by a cluster of psychological and somatic symptoms that begin during the late luteal phase of the menstrual cycle and disappear after the onset of menses. Since PMS might be caused by an alteration in the cyclical hormonal modifications and ovarian steroids are directly involved in the regulation of mood, affective and cognitive functions and influence neurotrophins expression, in particular the brain-derived neurotrophic factor (BDNF), we aimed to evaluate whether plasma BDNF levels in women with PMS differ from those of normally menstruating women without PMS. Sixty-two women were divided into two groups: one group of women (n=35) with PMS and one group (n=27) composed by normally menstruating women. Plasma samples were collected at day 7 (follicular phase) and day 21 (luteal phase) of the menstrual cycle. Plasma BDNF of the control group significantly increased (p<0.001) from the follicular phase (402.90±74.41pg/ml) to the luteal phase (1098.79±146.49pg/ml). On the other hand, in the PMS group plasma BDNF levels significantly decreased (p<0.001) from the follicular phase (412.45±78.35pg/ml) to the luteal phase (233.03±75.46pg/ml) Luteal BDNF levels of the PMS women were significantly lower than those of the control group (p<0.001). In women with PMS, plasma BDNF followed a decreasing trend during the ovarian cycle, in opposition to the increasing trend observed in women without PMS. The lower luteal BDNF levels of the PMS women might be a consequence of an altered hormonal response and might play a role in the onset of the symptoms PMS related.

Progestogens and brain: an update.

Each synthetic progestins has its own specific activities on different tissues, which can vary significantly between progestins of different classes and even within the same class. Indeed, different progestins may support or oppose the effects of estrogen depending on the tissue, thereby supporting the concept that the clinical selection of progestins for HRT is critical in determining potential positive or detrimental effects. These actions might be particularly relevant in the central nervous system (CNS) where progesterone (P) has pivotal roles besides reproduction and sexual behavior, going from neuropsychological effects to neuroprotective functions. Growing evidence supports the idea that synthetic progestins differ significantly in their brain effects, and clinical studies indicate that these differences also occur in women. Molecular and cellular characterization of the signaling properties of synthetic progestins in brain cells is therefore required and is hoped will lead to a better clinical utilization of the available compounds, as well as to new concepts in the engineering of new molecules. The aim of the present paper is to briefly review and compare neuroendocrine effects of progestogens with special reference to P metabolism into neuroactive steroids and the opioids system.

Androgen therapy in women: for whom and when

Androgens play a primary role in female physiopathology. The age-related reduction in the production of ovarian and adrenal androgens may significantly affect women’s health. The decline of circulating androgens results from a combination of two events: reduced ovarian production and aged-related decline in adrenal androgen synthesis. The relative androgen deficiency in pre- and postmenopausal women may induce impairment of sexual function, libido, well-being, energy and may contribute to reduced cognitive functions. Whether androgen deficiency also affects cardiovascular or bone biology in women during reproductive aging is still controversial. Both in the central nervous system and peripheral tissues, there are multiple ways whereby androgens target their specific actions through a particular tropism of the brain areas that are involved in sexual function, behavior and cognition. Among circulating available androgens that are involved in several domains of sexual response, adrenal androgens seem to be related to some sexual symptoms as well as diminished cognitive function in postmenopausal women. The possibilities of treating low sexual desire/hypoactive sexual desire disorder are multifaceted and should include the combination of both pharmacological treatments able to maximize biological signals that drive the sexual response as well as individualized psychosocial therapies to overcome personal and relational difficulties. Transdermal testosterone has been proved to be effective but the use of additional treatment like oral or vaginal dehydroepiandrosterone is still controversial, despite many evidences support it. The decision to treat premenopausal or postmenopausal women with signs/symptoms of androgen insufficiency is mainly based on the clinical judgment, together with estrogens co-administration and following informed consent related to the unknown long-term risks.

Sex Differences in Brain and Plasma β-Endorphin Content following Testosterone, Dihydrotestosterone and Estradiol Administration to Gonadectomized Rats

Aims: The present study aims at evaluating the effect of a 2-week treatment with testosterone (T), dihydrotestosterone (DHT) and estradiol valerate (E2V) on brain and plasma β-endorphin (β-END) concentrations in gonadectomized rats of both sexes. Methods: Eight groups of female and 8 groups of male Wistar rats were included. For each sex, 1 group of gonad-intact and 1 group of gonadectomized rats were employed as controls (placebo). The other groups received subcutaneous T at the doses of 10 and 100 μg/kg/day (female rats) or 1 and 5 mg/kg/day (male rats). Subcutaneous DHT was administered at the doses of 1, 10, 100 μg/kg/day (female rats) or 0.1, 1 and 5 mg/kg/day (male rats). E2V was administered subcutaneously at 0.05 mg/kg/day. β-END levels were measured in different brain areas and plasma. Results: Ovariectomy (OVX) induced a significant decrease in β-END in all brain areas analyzed as well as in plasma. Orchidectomy (OCX) reduced opioid concentration in the hypothalamus, anterior pituitary and neurointermediate lobe. In OVX rats, T replacement as well as E2V significantly increased β-END concentration in all brain areas and in plasma. In the OCX group, T and E2V did not influence β-END concentrations in different hypothalamic areas. However, they produced a significant rise in β-END levels in the hypothalamus, neurointermediate lobe, anterior pituitary and plasma. Conversely, DHT replacement did not affect β-END levels at any dose administered, either in males or females. Conclusions: The sensitivity of the endogenous opiatergic system to T administration seems to be sex-related. This effect is particularly evident in the brains of female animals where this endogenous endorphin elicits a much greater response than it does in males that have undergone gonadal steroid depletion and subsequent T replacement.

Paroxetine increases brain-derived neurotrophic factor in postmenopausal women.

Objective: Menopause is marked by a decline in ovarian function resulting in one or more climacteric symptoms. In the last few years, attention has been focused on the use of selective serotonin reuptake inhibitors (SSRIs) in the treatment of vasomotor symptoms associated with the menopausal transition. Thanks to the recent findings on the interaction between the serotoninergic system and neurotrophins, it has been suggested that brain-derived neurotrophic factor (BDNF) could contribute to the activity of SSRIs. Moreover, because endogenous gonadal hormones modulate both BDNF expression and serotonin biosynthesis and bioavailability and regulate brain functions like affective and cognitive functions, we proposed to evaluate the effects of a treatment with paroxetine, an SSRI, in a group of postmenopausal women and to clarify the possible relationship between paroxetine, plasma BDNF levels, and climacteric symptoms. Methods: A total of 119 postmenopausal women (age, 46-60 y; menopause age, 1-20 y) were included; 89 took paroxetine 10 mg/day for 6 months and 30 took estrogen + progestogen therapy (EPT) for 6 months. Blood samples were taken before the beginning of the therapy and at 3 and 6 months. The Green Climacteric Scale questionnaire was used to follow up womens clinical conditions. Results: Plasma BDNF levels significantly increased after 3 and 6 months of therapy (P < 0.001), although a negative correlation between plasma BDNF level and both age and menopause age persisted throughout the treatment. Moreover, a significant reduction in the Greene Climacteric Scale score was observed. In the EPT group, the plasma BDNF level significantly increased after 6 months of therapy. The plasma BDNF levels after 6 months of paroxetine were significantly lower than those after 6 months of EPT. Conclusions: The present data suggest that a low dose of paroxetine is effective in enhancing plasma BDNF levels, and this increase might have a role in improving climacteric symptoms, highlighting the possible role of BDNF in endocrinological and cognitive functions.

Brain-region responsiveness to DT56a (Femarelle) administration on allopregnanolone and opioid content in ovariectomized rats.

Objective: The natural selective estrogen receptor modulator DT56a (Femarelle), derived from soybean, has been shown to relieve menopausal vasomotor symptoms with no effect on sex steroid hormone levels or endometrial thickness. The purpose of the present study was to evaluate the neuroendocrine effect of DT56a administration through the evaluation of brain content of allopregnanolone (AP), an endogenous neurosteroid &ggr;-aminobutyric acid agonist with anxiolytic properties, and through the assessment of &bgr;-endorphin (&bgr;-END), the endogenous opioid implicated in pain mechanism, emotional state, and autonomic control. Methods: Five groups of Wistar ovariectomized (OVX) rats received one of the following treatments: oral DT56a administration at doses of 6, 12, 60, and 120 mg kg−1 day−1 or estradiol valerate (E2V) at a dose of 0.05 mg kg−1 day−1 for 14 days. One group of fertile and one group of OVX rats receiving placebo were used as controls. The concentration of AP was assessed in the frontal and parietal cortex, hippocampus, hypothalamus, anterior pituitary, and serum, whereas the content of &bgr;-END was evaluated in the frontal and parietal cortex, hippocampus, hypothalamus, neurointermediate lobe, anterior pituitary, and plasma. Results: DT56a increased AP levels in all brain areas analyzed and in serum, with a classical dose-related curve in comparison with OVX rats. In some brain areas, such as the frontal cortex, the parietal cortex, and the anterior pituitary, positive results were found even with the administration of a lower DT56a dose of 60 mg kg−1 day−1, attaining AP levels in the range of those in animals treated with E2V. Similarly, &bgr;-END levels were enhanced in selected brain areas such as the hippocampus, the hypothalamus, the neurointermediate lobe, and the anterior pituitary in comparison with those in OVX rats, in which the increase of the opioid was dose related and in the range of those in rats treated with E2V. Conclusions: This study demonstrated that DT56a positively affects brain neurosteroidogenesis and the opiatergic system: DT56a exerts an estrogen-like effect on selective areas related to mood, cognition, and homeostasis control, presenting a specific pattern of interaction with the brain function. These findings may, in part, explain the clinical effect of DT56a on menopausal symptoms.

Selective effect of chlormadinone acetate on brain allopregnanolone and opioids content.

BACKGROUND Synthetic progestins may have different biological actions depending on the target tissue, the dose administered or the coadministration of an estrogen molecule. The purpose of the present study was to evaluate the neuroendocrine effect of chlormadinone acetate (CMA) administration, analyzing the brain content of allopregnanolone (ALLO), an endogenous neurosteroid gamma-aminobutyric acid agonist with anxiolytic properties, and the brain level of beta-endorphin (beta-END), an endogenous opioid implicated in pain mechanism, emotional state and autonomic control. STUDY DESIGN Seven groups of Wistar ovariectomized (OVX) rats received one of the following treatments: oral CMA at a dose of 0.1, 0.5 or 1 mg/kg per day; estradiol valerate (E(2)V) at a dose of 0.05 mg/kg per day; CMA plus E(2)V (CMA 0.1 or 0.5 or 1 mg/kg per day + E(2)V 0.05 mg/kg per day) for 14 days. One group of fertile rats and one group of OVX rats were used as controls. RESULTS CMA increased ALLO content in the hippocampus and, when it was administered with E(2)V, also in the hypothalamus and anterior pituitary, evidence of a synergic effect with estrogens only in selective brain areas. beta-END content increased in the neurointermediate lobe and anterior pituitary after CMA administration, and it did not antagonize the positive, estrogen-induced increase of beta-END level. CONCLUSION CMA is effective in increasing ALLO and beta-END in selective brain areas showing a specific pattern of interaction with brain function, different compared to progesterone or to other synthetic progestins. In particular, CMA action on part of the limbic system (hippocampus and hypothalamus) and on the anterior pituitary support the hypothesis that this progestin might affect cognitive function, emotional state and autonomic control.

ORIGINAL RESEARCH—BASIC SCIENCE: Sexually Dimorphic Effects of Testosterone Administration on Brain Allopregnanolone in Gonadectomized Rats

INTRODUCTION Clinical and biological evidences have shown a wide range of neuroactive effects of testosterone administration. AIM Evaluation of the effects of 2-weeks treatment with testosterone (T), Dihydrotestosterone (DHT), and estradiol valerate (E2V) on brain and serum allopregnanolone (AP) in gonadectomized rats of both sexes. MAIN OUTCOME MEASURES AP levels were measured in frontal and parietal lobe, hippocampus, hypothalamus, anterior pituitary, and in serum. METHODS Eight groups of Wistar female and eight groups of Wistar male rats were included. For each sex, one group of fertile and one group of gonadectomized rats were employed as control receiving placebo. The others groups received subcutaneous T at the dose of 10 microg/kg/day and 100 microg/kg/day for female rats, and 1 mg/kg/day and 5 mg/kg/day for male rats, or DHT at the doses of 1 microg/kg/day, 10 microg/kg/day, and 100 microg/kg/day for females, and 0, 1 microg/kg/day, 1 mg/kg/day and 5 mg/kg/day for males, or E2V (0.05 mg/Kg/day). RESULTS Ovariectomy (OVX) and orchidectomy (OCX) induced a significant decrease in AP in all brain areas analyzed, as well as in serum. In OVX rats, T replacement, as well as E2V, significantly increased AP content in all brain areas and in plasma. In OCX, T and E2V did not actively result in influencing AP concentration in frontal and parietal lobe, while it produced a significant rise in AP levels in the hippocampus, hypothalamus, anterior pituitary, and serum. Conversely, DHT replacement had no affect on AP levels anywhere or at any administered dose, either in males or in female rats. CONCLUSIONS Gender difference and T therapy affect brain AP synthesis/release during the reproductive aging. This effect becomes particularly evident in the brain of ovariectomized animals, where the content of this specific neurosteroid is much more responsive than male animals to testosterone replacement.

ORIGINAL RESEARCHORIGINAL RESEARCH—BASIC SCIENCE: Sexually Dimorphic Effects of Testosterone Administration on Brain Allopregnanolone in Gonadectomized Rats

INTRODUCTION Clinical and biological evidences have shown a wide range of neuroactive effects of testosterone administration. AIM Evaluation of the effects of 2-weeks treatment with testosterone (T), Dihydrotestosterone (DHT), and estradiol valerate (E2V) on brain and serum allopregnanolone (AP) in gonadectomized rats of both sexes. MAIN OUTCOME MEASURES AP levels were measured in frontal and parietal lobe, hippocampus, hypothalamus, anterior pituitary, and in serum. METHODS Eight groups of Wistar female and eight groups of Wistar male rats were included. For each sex, one group of fertile and one group of gonadectomized rats were employed as control receiving placebo. The others groups received subcutaneous T at the dose of 10 microg/kg/day and 100 microg/kg/day for female rats, and 1 mg/kg/day and 5 mg/kg/day for male rats, or DHT at the doses of 1 microg/kg/day, 10 microg/kg/day, and 100 microg/kg/day for females, and 0, 1 microg/kg/day, 1 mg/kg/day and 5 mg/kg/day for males, or E2V (0.05 mg/Kg/day). RESULTS Ovariectomy (OVX) and orchidectomy (OCX) induced a significant decrease in AP in all brain areas analyzed, as well as in serum. In OVX rats, T replacement, as well as E2V, significantly increased AP content in all brain areas and in plasma. In OCX, T and E2V did not actively result in influencing AP concentration in frontal and parietal lobe, while it produced a significant rise in AP levels in the hippocampus, hypothalamus, anterior pituitary, and serum. Conversely, DHT replacement had no affect on AP levels anywhere or at any administered dose, either in males or in female rats. CONCLUSIONS Gender difference and T therapy affect brain AP synthesis/release during the reproductive aging. This effect becomes particularly evident in the brain of ovariectomized animals, where the content of this specific neurosteroid is much more responsive than male animals to testosterone replacement.