The brain as a new frontier for reproductive endocrinology.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to A R Genazzani.
Explore the source record for details and available documents.
OBJECTIVE: To evaluate whether activin A, inhibin A, and inhibin B levels in maternal and umbilical artery serum change according to the mode of delivery. DESIGN: Maternal and cord blood specimens were collected at term after spontaneous labour and vaginal delivery, or elective caesarean section. SETTING: Universities of Pisa, Turin, Naples and Udine. POPULATION: Forty-two healthy pregnant women, at 3940 weeks of gestation, divided into two subgroups: group 1 vaginal delivery (n = 21), were delivered of 10 female and 11 male infants; group 2 elective caesarean section (n = 21), were delivered of 11 female and 10 male infants. MAIN OUTCOME MEASURES: Serum activin A, inhibin A, inhibin B concentrations in maternal and umbilical cord blood. RESULTS: At vaginal delivery, maternal serum inhibin A and inhibin B levels were lower and activin A levels higher than at elective caesarean section. Maternal levels of activin A, inhibin A and inhibin B were constantly higher than in umbilical arterial blood, independent of the mode of delivery. No significant difference was observed in umbilical arterial serum levels of the three proteins between the two modes of delivery. Umbilical arterial serum activin A and inhibin A concentrations did not show a significant difference between male and female infants in either vaginal or caesarean section, but male infants showed inhibin B levels significantly higher than female, independent of the mode of delivery. CONCLUSIONS: In the presence of active labour, the human placenta secretes larger amounts of activin A and lesser amounts of inhibin A and inhibin B into the maternal circulation. Inhibin-related proteins in the fetal circulation do not show differences according to the mode of delivery, suggesting that they have a different method of production or metabolic rate compared with maternal activin and inhibins.
Allopregnanolone is the best characterized among neurosteroids, and its role in the control of neuroendocrine axes has attracted increasing interest recently. However, there is no available information about circulating levels of allopregnanolone during infancy, childhood and puberty. We studied two groups of children: 1) those aged between 0 and 2 y (n = 72), and 2) those aged between 6 and 18 y, at different Tanner's stages (n = 82). In each of these patients, serum allopregnanolone, progesterone, cortisol, and dehydroepiandrosterone levels were evaluated after informed consent; allopregnanolone was measured by RIA after acid extraction on cartridge. There was no significant variation of serum allopregnanolone levels either in male and female children during the first 2 y of life. Furthermore, although serum dehydroepiandrosterone levels showed a significant decrease, inversely correlated with age of the children (p < 0.01), serum cortisol and progesterone levels showed a significant age-related increase during the first 2 y of life. Cortisol and allopregnanolone levels were positively correlated (p < 0.01). During puberty, we observed a progressive increase in serum allopregnanolone levels in both boys and in girls, which were higher at Tanner' s stage IV-V (0.7+/-0.01 nM; mean +/- SEM) than at stages I-II (0.32+/-0.02 nM; p < 0.01); mean levels were significantly higher at puberty than in the first 2 y of life (p < 0.01). Furthermore, during puberty, serum progesterone and dehydroepiandrosterone levels also increased progressively with age in both boys and girls. Allopregnanolone and dehydroepiandrosterone levels were positively correlated throughout puberty. The present results indicate that serum allopregnanolone levels do not change during the first 2 y of life but increase during pubertal development, suggesting that this steroid may be involved in the adaptive neuroendocrine mechanisms related to puberty.
Selective estrogen receptors modulators (SERMs) are a series of new compounds exerting estrogenic or anti-estrogenic effects in different tissues. 17Beta-estradiol is known to inhibit endothelial vascular cell adhesion molecule (VCAM)-1 expression. We studied the relative effects of the raloxifene analogue LY117018 and of tamoxifen on lipopolysaccharide (LPS)-induced VCAM-1 expression in cultured human saphenous vein endothelial cells (HSVEC) and on HSVEC adhesiveness towards U937 monocytoid cells. We here demonstrate a concentration-dependent inhibitory action on VCAM-1 protein expression both for 17beta-estradiol and LY117018. The action of both compounds was blocked by the pure anti-estrogen ICI 182,780. LY117018 did not antagonize 17beta-estradiol activity. On the contrary, tamoxifen had no effects of his own. Both 17beta-estradiol and LY117018 inhibited HSVEC VCAM-1 expression at the mRNA level, while tamoxifen was ineffective. Finally, 17beta-estradiol and LY117018, but not tamoxifen, inhibited HSVEC adhesiveness towards U937 monocytoid cells induced by LPS stimulation. Therefore, only some SERMs have potential anti-atherogenic actions exerted directly at the vascular level through the regulation of endothelial cell adhesion molecules expression and of endothelial-leukocyte interactions.
Urocortin is a new member of the CRF family. Multiple biological effects for urocortin have been shown in rats and in some in vitro models, showing a modulatory role in hormonal and behavioral functions. Human placenta expresses urocortin, but no information is available on the possible local biological actions. The aim of the present study was to evaluate the effect of urocortin on placental ACTH and prostaglandin (PG) secretion, as well as on myometrial contractility. Various in vitro models were used. For investigating the effect of urocortin on ACTH release, primary cultures of human trophoblast cells were used. Culture media, collected before and after 3 h exposure to different doses of urocortin and ACTH, were measured by RIA. Trophoblast tissue explants were incubated for 24 h in the presence of increasing doses of urocortin, and prostaglandin E2 (PGE2) levels were measured by RIA. Strips of myometrial tissue were incubated in an organ bath and connected to an isometric smooth-muscle transducer in the presence of urocortin, with or without prostaglandin F2alpha (PGF2a). In all these experiments, the effect of astressin (a CRF receptor antagonist) on urocortin-induced actions and the effect of equimolar doses of CRF were evaluated. A dose-related increase of trophoblast ACTH or PGE2 was induced by urocortin, whereas astressin inhibited urocortin-stimulated ACTH or PGE2 release. Equimolar doses of CRF showed a similar effect on both ACTH and PGE2. Urocortin increased PGF2alpha-induced myometrial contractility, and this effect was completely abolished by the addition of astressin. The present study showed that human urocortin stimulates placental secretion of ACTH and PGE2, and modulates myometrial contractility, suggesting a role for this peptide in placental and intrauterine CRF pathways.
Corticotropin-releasing factor (CRF) plays a key role in the modulation of fetal-placental unit function during human pregnancy. CRF has a potent vasoactive action on fetal-placental circulation. As products secreted from endothelial cells affect vascular wall reactivity, we investigated whether cultured human umbilical vein endothelial cells (HUVEC) may represent a source and a target for CRF. With RT-PCR we showed that HUVEC express CRF and CRF receptor type 2 messenger ribonucleic acids. Cultured HUVEC also released CRF peptide in a time-dependent way, and the CRF release was differently regulated by various molecules. Dexamethasone decreased CRF release, whereas progesterone and 17beta-estradiol markedly increased it. Forskolin and PGF2alpha were potent stimulators of CRF release from HUVEC. Among the peptides, CRF secretion was stimulated by interleukin-1beta and by endothelin-1. Our study shows for the first time that HUVEC express CRF messenger ribonucleic acid and peptide as well as the CRF R2 gene, and that CRF release is differentially regulated by several distinct molecules. We here propose that CRF has a role in the regulation of the fetal-placental circulation.
The aim of this study was to evaluate how, in patients with polycystic ovary syndrome, the number of small subcapsular follicles correlates with uterine and ovarian blood flow and with specific hormonal parameters. At an ultrasonographic evaluation, 30 patients with polycystic ovary syndrome showed 5-10 (group I; n = 14) or > 10 (group II; n = 16) small follicles. These patients underwent ultrasonographic (ovarian volume and stroma echodensity; number, diameter and distribution of follicles) and color Doppler (uterine and intraovarian vessels) analyses, and hormonal assay. In group II, significantly lower pulsatility index values than in group I were observed in the ovarian stromal arteries. The Ferriman-Gallwey score, plasma androstenedione level and luteinizing hormone/follicle stimulating hormone (LH/FSH) ratio results were significantly higher in group II than in group I. Androstenedione plasma levels correlated with the number of small follicles. Furthermore, the LH/FSH ratio correlated with both the number of small follicles and the stromal artery pulsatility index. The combined assessment of ovarian morphology by transvaginal ultrasound and color Doppler may provide insight into the pathological state of polycystic ovary syndrome.
The aim of the study was to evaluate the plasma thromboxane and plasma viscosity in relation with Doppler flow parameters in postmenopausal patients treated with hormone replacement therapy. Thirty-two postmenopausal (follicle-stimulating hormone > 40 IU/l and estradiol < 100 pmol/l) women (mean age +/- SD, 54.7 +/- 2.9 years) participated in the study and were submitted to continuous estradiol transdermal supplementation and 12-day courses of medroxyprogesterone acetate every second month. Doppler resistances at the level of the uterine and internal carotid arteries, thromboxane plasma levels and plasma viscosity were analyzed in basal condition and after 1, 3 and 6 months. During hormone supplementation, the pulsatility index significantly decreased at the level of the analyzed arteries. Similarly, plasma thromboxane levels and plasma viscosity were significantly reduced. Significant correlations were found between thromboxane plasma concentrations, plasma viscosity and uterine artery resistances. Thus hormone replacement therapy seems to be responsible for both direct and indirect modifications at the level of the vessel wall physiology.
The effects of hormone-replacement therapy on the Doppler flow parameters of the ophthalmic artery in postmenopausal women were studied and compared with those registered at the level of the internal carotid and uterine arteries. Fifty-seven postmenopausal patients were submitted to continuous estradiol transdermal supplementation and 12-day courses of medroxyprogesterone acetate. During the estrogen phase of hormone-replacement therapy all patients underwent (at 1, 3 and 6 months after the beginning of hormone-replacement therapy) transvaginal ultrasonographic evaluation of the pelvic organs and of endometrial thickness. On the same day, they underwent color Doppler analysis of the blood flow impedance of the uterine, internal carotid and ophthalmic arteries. Estradiol plasma concentrations were assayed on the day that ultrasonographic and Doppler examinations took place. The pulsatility index of all the arteries improved, from baseline values, during the therapy and attained stable values compared to those after the first month of treatment. Furthermore, at the level of the internal carotid and ophthalmic arteries, a significant increase of the peak systolic blood flow velocity (Vmax) was observed over the 6 months of therapy. Doppler studies of the ophthalmic artery are capable of affording specific and precise pathophysiologic information to assess peripheral intracranial blood flow variations. Furthermore, such studies may be useful in monitoring hormone-replacement therapy effects on cerebral perfusion.
Raloxifene is a selective estrogen receptor modulator with a benzothiophene structure, that exerts an estrogen-like action on some target tissues and an anti-estrogenic action on the uterus and breasts. A limited number of data are available on the effect of raloxifene on neuroendocrine function. Since beta-endorphin (beta-EP) is considered a marker of neuroendocrine function, the aim of the present study was to evaluate the effects of a 14 day treatment with a raloxifene analog, LY 117018, on beta-EP content in the hypothalamus, hippocampus, anterior and neuro-intermediate pituitary lobe, and in the plasma of fertile and ovariectomized (ovx) rats. The effect of LY 117018 in ovx rats was compared to that of 17 beta-estradiol. beta-EP contents were measured by a specific radioimmunoassay. While ovariectomy determined a significant decrease in beta-EP levels in the anterior and neurointermediate pituitary lobe and plasma (p < 0.01), no changes of beta-EP content in the hypothalamus and hippocampus were found. The administration of 17 beta-estradiol or LY 117018 in ovx rats significantly increased beta-EP concentration in the anterior and neurointermediate pituitary lobe, in the hypothalamus and plasma (p < 0.01), though they did not significantly modify hippocampal beta-EP content. When LY 117018 was administered together with 17 beta-estradiol in ovx animals, a clear anti-estrogenic effect in all organs and in plasma was observed, resulting in significantly lower beta-EP content with respect to the group treated with 17 beta-estradiol alone (p < 0.01). The chronic administration of LY 117018 in fertile rats significantly decreased beta-EP content in the anterior pituitary, hippocampus and plasma (p < 0.01), while it increased beta-EP hypothalamic content and did not change beta-EP content in the neurointermediate lobe. In conclusion, raloxifene analog LY 117018 has an estrogen-like action on neuroendocrine opiatergic pathways when administered alone in ovx rats, while it exerts an anti-estrogen effect in fertile or in ovx rats treated with 17 beta-estradiol.
The study aims to evaluate whether serum vascular endothelial growth factor (VEGF) levels, before treatment with gonadotropins, may be considered a predictive marker of moderate ovarian hyperstimulation syndrome (OHSS). At the University of Pisa hospital infertility unit we have retrospectively selected 10 patients who developed moderate forms of OHSS and 30 control patients who presented a normal response to ovarian stimulation among 400 women undergoing in vitro fertilization (IVF). Serum samples were collected before starting pFSH administration (150-300 IU/day). VEGF levels in serum were measured. No statistically significant difference was found between the serum VEGF levels of patients who developed moderate forms of OHSS and women without any symptoms of the syndrome. Further, serum VEGF concentrations were not significantly correlated with the age of the patients, the number of international units of FSH administered during the cycle of stimulation, the follicle and oocyte numbers counted on the day of the egg retrieval or estradiol levels detected on the same day. This study demonstrates that serum VEGF levels, before starting gonadotropin treatment, are not predictive of the subsequent development of moderate forms of ovarian hyperstimulation syndrome.
Explore the source record for details and available documents.
OBJECTIVE: To estimate the effects of climacteric modifications on body weight and fat distribution. METHODS: From 8764 women attending the authors' Menopause Clinic, 1075 untreated, normal healthy women were selected and divided into three groups: premenopausal (n = 380), perimenopausal (n = 263) and postmenopausal (n = 432). The total body fat tissue mass and distribution were analyzed using the dual energy X-ray method. RESULTS: Body weight and body mass index (BMI) were significantly higher in perimenopausal and postmenopausal than in premenopausal women. The mean total body fat and the percentage of fat with respect to soft tissue were significantly (p < 0.05) higher in the perimenopausal and postmenopausal groups than in the premenopausal group. The amount of fat tissue and the regional fat percentage with respect to total fat tissue were higher in the trunk (p < 0.05) and arm (p < 0.05) regions in perimenopausal and postmenopausal than in premenopausal women. In the postmenopausal group, the leg fat tissue was significantly (p < 0.05) less than in the premenopausal and perimenopausal groups. Total body and leg lean tissue was significantly (p < 0.01) less in postmenopausal than in premenopausal and perimenopausal women. In the premenopausal group, body weight and BMI were positively correlated with age (r = 0.37 and r = 0.54, respectively). No significant correlations were observed in the perimenopausal group. In postmenopausal women, body weight and BMI were loosely correlated with age (r = 0.13 and r = 0.11, respectively). In three groups of 63 age-matched women, with similar BMI, the percentage of total body fat with respect to soft tissue was significantly (p < 0.001) higher in the perimenopausal and postmenopausal groups than in the premenopausal group. Regarding body fat distribution, the percentage of fat with respect to total fat tissue was significantly higher in the trunk (p < 0.001) region in perimenopausal and postmenopausal women than in premenopausal women. In the leg region, the percentage of fat with respect to total fat tissue was significantly (p < 0.05) higher in the premenopausal group than in the postmenopausal group. In the arm region, a slight but not significant (p < 0.08) difference was shown in fat distribution among the three groups. CONCLUSIONS: Climacteric changes rather than the aging process are relevant for prediction of body weight and fat distribution, especially for perimenopausal and postmenopausal women, who show a shift to a central, android fat distribution.
OBJECTIVES: Our aim was to assess the effects of a combined oral contraceptive (OC) preparation on bone quantitative ultrasound and biochemical markers of bone metabolism in perimenopausal women. DESIGN: Bone biochemical markers and bone quantitative ultrasound were evaluated in a longitudinal 2-year follow-up study conducted in healthy, normally menstruating perimenopausal women, perimenopausal oligomenorrheic women, and age-matched oral contraceptive-treated women (20 micrograms of ethinyl estradiol plus 0.15 mg desogestrel). The results were analyzed by factorial or repeated-measures analysis of variance, as appropriate. RESULTS: In normal women, there were no significant modifications in menstrual cycle, plasma FSH and estradiol levels, biochemical markers of bone turnover, and bone quantitative ultrasound. Conversely, in oligomenorrheic women, an increase in the cycle length with a concomitant rise in circulating plasma FSH and parallel decrease of plasma estradiol levels was evident. In this group, an increase in both urinary excretion of hydroxyproline and plasma osteocalcin levels paralleled a decrease in bone quantitative ultrasound. In perimenopausal OC-treated women, the pattern of osteocalcin and urinary excretion of hydroxyproline showed a slight decrease, whereas bone quantitative ultrasound did not show any significant modification. CONCLUSION: Perimenopausal OC administration can prevent the increase in bone turnover and the decrease in bone quantitative ultrasound that follow the perimenopausal impairment of ovarian function.
Because of the association of oral contraceptives (OC) and cigarette smoking with an increased thrombotic risk, we evaluated thromboxane (TX) and prostacyclin urinary (u) metabolites, as in vivo indices of platelet-vessel wall interactions, in women assigned to third generation OC. Twenty-eight women (15 smokers) underwent a 6-month trial of 30 microg ethinylestradiol plus 0.150 mg desogestrel. Cotinine plasma levels were elevated only in persons classified as smokers and serum TXB2 determination confirmed the absence of cyclooxygenase inhibition throughout the study. u-TXB2 and 11-dehydro-TXB2 were higher in smokers than in non-smokers. OC decreased u-11-dehydro-TXB2 both in smokers (from (pg/micromol creatinine) 35.1+/-6.9 to 15.8+/-2.8; P<0.025) and non-smokers (from 31.7+/-9.8 to 20.6+/-4.8, P = N.S.). u-6-keto-prostaglandin(PG)F1alpha excretion, also higher in smokers compared to non-smokers, was also reduced after OC in smokers (from (pg/micromol creatinine) 24.3+/-5.2 to 14.8+/-2.3; P<0.05). Smokers also had a trend to higher u-2,3-dinor-6-keto-PGF1alpha, marginally reduced by OC. Thus, the OC regimen used here improves - if anything - platelet vessel wall interactions as assessed by prostanoid production in vivo. The prothrombotic tendency associated with the use of OC in smokers does not appear to be mediated by changes in platelet-vessel wall interactions.
The concurret use of smoking and oral contraceptives affects the hemostatic balance, thereby inducing a thrombophilic state. In order to clarify the effects of this association on the hemostatic system, the possible changes in the markers of activation of coagulation (thrombin-antithrombin III complexes and prothrombin fragment F1+2) were evaluated in 35 women given a third-generation oral contraceptive for 6 months; 13 of these women (37.1%) were mild or moderate smokers. No differences were found in basal levels of the coagulation and fibrinolytic parameters between smokers and non-smokers. During oral contraceptive administration, both F1+2 fragment and thrombin-antithrombin III complex concentrations significantly increased both in smokers and in non-smokers (p < 0.01). Fibrinogen plasma levels increased in both groups (p < 0.01). Antithrombin III activity was reduced in both groups during treatment, but the difference was significant only in smokers (p < 0.05). Although the sample size of smokers was too small to draw definitive conclusions, present results appeared to confirm previous data about the effect of the concurrent use of smoking and oral contraceptives on antithrombin III levels, but did not demonstrate any additional effect of moderate smoking on the activation of the clotting system induced by this oral contraceptive preparation.
Explore the source record for details and available documents.
OBJECTIVES: A progressive decline of plasma dehydroepiandrosterone (DHEA) levels occurs in women during aging related to the reduction of adrenocortical secretion. A specific action of DHEA on the central nervous system (CNS) is suggested by the improvement of psychological and physical well-being in postmenopausal women after DHEA supplementation. The aim of the present study was to investigate the neuroendocrine effects of short-term DHEA supplementation in postmenopausal women, evaluating changes of plasma beta-endorphin (beta-EP) and growth hormone (GH) before and after oral DHEA (100 mg/day) for 7 days in postmenopausal women (n = 6). METHODS: Before and after 7 days of DHEA supplementation, postmenopausal women underwent a neuroendocrine test with clonidine, an alpha 2 presinaptic agonist for adrenergic system (1.25 mg i.v.). Basal plasma DHEA, androstenedione (A), testosterone (T), estrone (E1) and estradiol (E2) levels were evaluated before and after treatment, while plasma beta-EP and GH levels were measured before and 15, 30, 45, 60 and 90 min after clonidine injection. RESULTS: Basal plasma beta-EP and GH levels did not show a significant difference before and after short-term DHEA administration, while circulating A, T, E1 and E2 significantly increased after treatment. The clonidine test induced a significant increase of plasma beta-EP levels in women after receiving DHEA supplementation but not before; conversely, plasma GM levels increased both before and after treatment. CONCLUSIONS: The present study indicates that short-term DHEA supplementation in postmenopausal women is able to restore the impaired response of pituitary beta-EP to clonidine, an alpha 2 presinaptic agonist. According to these data it is possible to hypothesize that DHEA could play a role in the psychological and physical well-being of postmenopausal women acting via a restoration of neuroendocrine control of antero-pituitary beta-EP secretion.