Evidence that Melatonin Increases Inhibin Beta-A and Follistatin Gene Expression in Ovaries of Pinealectomized Rats.

Melatonin plays an important role in the regulation of ovarian function including oocyte maturation in different mammalian species. Many studies indicate that melatonin has an impact on the ovarian function of a variety of ovarian cells. However, the information on the exact mechanism and involved hormones is low. To evaluate inhibin beta-A (INHBA) and follistatin (FST) expression in the ovaries of pinealectomized rats treated with melatonin, thirty adult female Wistar rats were randomized into three groups of ten animals each: group 1 (GSh), sham-operated controls receiving vehicle; group 2 (GPx), pinealectomized animals receiving vehicle; and group 3 (GPxMe), pinealectomized animals receiving replacement melatonin (1.0 mg/kg body weight. It was assumed that each animal drank 6.5 ± 1.2 ml per night and weighs approximately 300 g.) for 60 consecutive days. The ovaries were collected for mRNA abundance and protein of INHBA and FST by qRT-PCR and immunohistochemical analyses, respectively. Treatment with melatonin resulted in the upregulation of INHBA and FST genes in the ovarian tissue of the melatonin-treated animals (GPxMe), when compared with GPx. These findings were then confirmed by analyzing the expression of protein by immunohistochemical analyses, which revealed higher immunoreactivity of INHBA and FST in GPxMe animals in the follicular cells compared with GSh and GPx rats. Melatonin increases the expression of INHBA and FST in the ovaries of pinealectomized female rats.

Does melatonin influence the apoptosis in rat uterus of animals exposed to continuous light?

Melatonin has been described as a protective agent against cell death and oxidative stress in different tissues, including in the reproductive system. However, the information on the action of this hormone in rat uterine apoptosis is low. Our objective was to evaluate the effects of melatonin on mechanisms of cell death in uterus of rats exposed to continuous light stress. Twenty adult Wistar rats were divided into two groups: GContr (vehicle control) and GExp which were treated with melatonin (0.4 mg/mL), both were exposed to continuous light for 90 days. The uterus was removed and processed for quantitative real time PCR (qRT-PCR), using PCR-array plates of the apoptosis pathway; for immunohistochemistry and TUNEL. The results of qRT-PCR of GEXP group showed up-regulation of 13 and 7, pro-apoptotic and anti-apoptotic genes, respectively, compared to GContr group. No difference in pro-apoptotic proteins (Bax, Fas and Faslg) expression was observed by immunohistochemistry, although the number of TUNEL-positive cells was lower in the group treated with melatonin compared to the group not treated with this hormone. Our data suggest that melatonin influences the mechanism and decreases the apoptosis in uterus of rats exposed to continuous light.

Melatonin influences on steroidogenic gene expression in the ovary of pinealectomized rats.

OBJECTIVE: To analyze the expression of genes related to steroidogenesis in the ovary of pinealectomized rats. DESIGN: Experimental research. SETTING: University research laboratory. ANIMAL(S): Thirty female adult rats. INTERVENTION(S): Administration of vehicle (GI), pinealectomy with vehicle (GII), or pinealectomy with melatonin replacement (10 µg/night) for 60 consecutive days (GIII), then euthanasia after 2 months of treatment, ovary collection complementary DNA microarray analyses, confirmatory quantitative reverse-transcriptase polymerase chain reaction analyses, and immunohistochemical analyses for localizing steroidogenesis changes in the ovary. MAIN OUTCOME MEASURE(S): Biologic molecular study followed by immunohistochemical analysis. RESULT(S): The changes in the expression of CYP11A1, CYP17A1, and CYP19A1 after pinealectomy (GII) compared with control (GI) showed the Cyp17a1 expression level increased in the theca interna and interstitial cells in the GII rats compared with the other groups. CONCLUSION(S): Melatonin deprivation (pinealectomy) or administration may influence the ovarian CYP17A1 expression and steroidogenesis.

Evaluation of FAS and caspase-3 in the endometrial tissue of patients with idiopathic infertility and recurrent pregnancy loss.

OBJECTIVE: To investigate expression of BcL-2, FAS, FAS ligand (FASL) and cleaved caspase-3 in the endometrial tissue of women with idiopathic infertility (with two consecutive failed cycles of in vitro fertilization) and women with idiopathic recurrent pregnancy loss. The control group consisted of fertile women. STUDY DESIGN: Endometrial tissue samples from fertile women (n=25), women with idiopathic infertility (n=25) and women with idiopathic recurrent pregnancy loss (n=25) were collected on the seventh or eighth postovulatory day of their menstrual cycles for evaluation. Expression of BcL-2, FAS, FASL and cleaved caspase-3 was assessed using immunohistochemical methods. RESULTS: Expression of BcL-2 and FAS was significantly higher and lower, respectively, in the women with idiopathic infertility than in the other groups (p<0.01). Expression of cleaved caspase-3 was significantly lower in the women with idiopathic infertility than in the other groups (p<0.01). Expression of FASL was similar in all three groups. CONCLUSION: Disturbances in endometrial apoptosis may be a contributing factor in patients with idiopathic infertility and recurrent pregnancy loss.

Effects of melatonin on histomorphology and on the expression of steroid receptors, VEGF, and PCNA in ovaries of pinealectomized female rats.

OBJECTIVE: To evaluate the effect of melatonin both on the ovaries of pinealectomized female rats through histomorphometric analysis and on steroid receptors, proliferating cell nuclear antigen (PCNA), and vascular endothelial growth factor (VEGF) expression. DESIGN: Experimental study. SETTING: Federal University of São Paulo, Brazil. ANIMAL(S): Forty female rats. INTERVENTION(S): Forty rats were divided equally into four groups: GI-vehicle without surgery; GII--surgery without removal of the pineal gland (sham); GIII--pinealectomized with vehicle; and GIV--pinealectomized with melatonin treatment. After treatment for 3 consecutive months, the animals were killed and their ovaries removed for analysis. MAIN OUTCOME MEASURE(S): Estrogen and progesterone receptors, histologic and immunohistochemical analysis. RESULT(S): The GIII samples presented signals of proliferation on ovarian surface epithelium and interstitial cells as well as high expressions of PCNA and VEGF in those structures compared with GI, GII, and GIV. Also, the levels of progesterone receptor (fmol/g) in ovaries of GIII (250.6 ± 32.4) were significantly lower than in those of GI (429.0 ± 23,8), GII (442.3 ± 30.2), and GIV (564.1 ± 78.7). The levels of progesterone in GIII were superior to those in GI, GII, and GIV. CONCLUSION(S): Our findings suggest that melatonin may attenuate proliferation in ovarian structures and increase the number of luteal bodies as well as the levels of progesterone receptor.

Effects of estradiol on the cognitive function of postmenopausal women.

OBJECTIVE: To analyze the effect of estrogen on the cognitive function of postmenopausal women through psychometric tests. METHODS: Seventy-four postmenopausal women were divided into two groups: (G1) estrogen group (n = 34), treated with 2 mg 17 beta-estradiol; (G2) placebo group (n = 31), treated with inactive substance. All the participants were submitted, before and after treatment, to psychometric tests, Greene's Scale of Climacteric Symptoms and the Hamilton Scale for depression. Statistical analysis was performed using the Mann-Whitney test and Student's t-test. In order to evaluate the degree of improvement of symptoms or depression after estrogen treatment, Spearman's correlation coefficient was calculated. RESULTS: A few psychometric tests (immediate and late recall of story, Trailmaking A and B, FAS, Stroop, Bells tests) showed post-intervention improvement, but these were not significant when compared to the placebo group's data. The estrogen group's climacteric symptoms were mitigated in comparison to placebo's, but there was no significant difference between the two groups on the Hamilton Scale. Reduction in climacteric symptoms was associated with improvement in executive function performance as evaluated by the Stroop test. CONCLUSION: Our results suggest estrogen improves the cognitive function, possibly due to a decrease in vasomotor symptoms.

[Melatonin effects on the female genital system: a brief review]. / Efeitos da melatonina no sistema genital feminino: breve revisão.

Melatonin is secreted by the pineal gland and this is linked to the day/night cycle. It is an antioxidant and plays a fundamental role in the regulation of the jet-lag stage, in several physiological reactions and in control of the biologic rhythm. Human melatonin has an important influence on the female genital system. In fact, melatonin may influence production and action of steroids, modifying cellular signalization on the target tissue. There are many evidences that the melatonin therapy may be interfering with neoplasia development, mainly of the estrogen-dependent tumor. This paper aims to analyze the actions of melatonin on the neuroendocrine, immunological and cardiovascular systems, as well as on the reproductive function.

Efeitos da melatonina no sistema genital feminino: breve revisão / Melatonin effects on the female genital system: a brief review

A melatonina é um hormônio produzido pela glândula pineal, cuja secreção está diretamente relacionada ao ciclo claro-escuro. É um poderoso antioxidante e tem papel fundamental na regulação do estado sono/vigília, do ritmo de vários processos fisiológicos, participando do controle do relógio biológico, inclusive nos seres humanos. Ressalta-se que há evidências da sua ação no sistema genital feminino, influenciando a função ovariana e a fertilidade. De fato, este hormônio interage com esteróides sexuais, como o estrogênio, modificando a sinalização celular e a resposta no tecido alvo. Estudos clínicos sugerem que o tratamento com a melatonina interviria com a evolução de neoplasia-dependente do estrogênio. O objetivo dessa revisão é analisar as principais ações da melatonina no sistema neuroendócrino, no ciclo sono-vigília, no sistema imunológico, no sistema cardiovascular, bem como no sistema reprodutor.

Melatonin is secreted by the pineal gland and this is linked to the day/night cycle. It is an antioxidant and plays a fundamental role in the regulation of the jet-lag stage, in several physiological reactions and in control of the biologic rhythm. Human melatonin has an important influence on the female genital system. In fact, melatonin may influence production and action of steroids, modifying cellular signalization on the target tissue. There are many evidences that the melatonin therapy may be interfering with neoplasia development, mainly of the estrogen-dependent tumor. This paper aims to analyze the actions of melatonin on the neuroendocrine, immunological and cardiovascular systems, as well as on the reproductive function.

Effects of glucosamine on the tibial epiphyseal disk of ovariectomized rats: morphologic and morphometric analysis.

OBJECTIVE: The aim of this study was to analyze the effect of glucosamine sulfate on the tibial epiphyseal disk of the ovariectomized rats. METHODS: After ovariectomy (OVx), 28 female rats were randomly divided into 4 experimental groups with 7 animals each, treated as follows: OVx 21 - vehicle (NaCl 0.9%) 0.5 mL/day) for 21 days; OVx GS21 - 230 mg/kg/day glucosamine sulphate for 21 days; OVx 45 - treated with NaCl 0.9% as above for 45 days; and OVx - GS45230 mg/kg/day glucosamine sulphate for 45 days. Seven intact animals in the proestrous phase were used as controls (CG). Upon treatment completion, the animals were sacrificed and the left knee joint was dissected and prepared for histological analysis. RESULTS: The percentage of remaining cartilage in new bone of the CG; that found in THE OVx GS45 group was significantly less than that of the OVx 21, OVx GS21, and OVx 45 groups. The percentage of trabecular bone in proestrous animals was the highest. The OVx GS45 group showed higher values compared with the other ovariectomized groups. These results were paralleled by the findings regarding the cells of the proliferative zone, since the CG had the highest values, and the values of the OVx GS45 group were greater than those of the OVx 21, OVx GS21, and OVx 45 groups. CONCLUSION: Our studies suggested that glucosamine may stimulate tibial cartilage and bone growth after ovariectomy in rats.

Effects of glucosamine on the tibial epiphyseal disk of ovariectomized rats: morphologic and morphometric analysis

OBJECTIVE: The aim of this study was to analyze the effect of glucosamine sulfate on the tibial epiphyseal disk of the ovariectomized rats. METHODS: After ovariectomy (OVx), 28 female rats were randomly divided into 4 experimental groups with 7 animals each, treated as follows: OVx 21 - vehicle (NaCl 0.9 percent) 0.5 mL/day) for 21 days; OVx GS21 - 230 mg/kg/day glucosamine sulphate for 21 days; OVx 45 - treated with NaCl 0.9 percent as above for 45 days; and OVx - GS45230 mg/kg/day glucosamine sulphate for 45 days. Seven intact animals in the proestrous phase were used as controls (CG). Upon treatment completion, the animals were sacrificed and the left knee joint was dissected and prepared for histological analysis. RESULTS: The percentage of remaining cartilage in new bone of the CG; that found in THE OVx GS45 group was significantly less than that of the OVx 21, OVx GS21, and OVx 45 groups. The percentage of trabecular bone in proestrous animals was the highest. The OVx GS45 group showed higher values compared with the other ovariectomized groups. These results were paralleled by the findings regarding the cells of the proliferative zone, since the CG had the highest values, and the values of the OVx GS45 group were greater than those of the OVx 21, OVx GS21, and OVx 45 groups. CONCLUSION: Our studies suggested that glucosamine may stimulate tibial cartilage and bone growth after ovariectomy in rats.

OBJETIVO: O alvo deste estudo foi analisar o efeito do sulfato de glicosamina no disco epifisário da tíbia em ratas ooforectomizadas. MÉTODOS: Após a ooforectomia (OVx), 28 ratas foram aleatoriamente divididas em 4 grupos experimentais de 7 animais cada, tratados da seguinte maneira: OVx 21 - veículo (0,5ml de NaCl 0.9 por cento ip uma vez ao dia) por 21 dias; OVx GS21 230 - mg/kg peso corporal por dia de sulfato de glicosamina, 21 dias; OVx 45 - tratados com NaCl 0.9 por cento igual ao grupo OVx 21, por 45 dias; e OVx GS45 - 230 mg/kg peso corporal por dia com sulfato de glicosamina, 45 dias. Sete animais intactos, na fase de proestro, foram usados como controle (CG). Ao completar o tratamento, os animais foram sacrificados e a articulação do joelho esquerdo foi dissecada e preparada para análise histológica. RESULTADOS: A porcentagem de cartilagem remanescente no novo osso do CG foi a menor. Os achados no grupo OVx GS45 foi significantemente menor do que no grupo OVx 21, OVx GS21 e OVx 45. A porcentagem de osso trabecular nos animais em pró-estro foi a maior. O grupo OVx GS45 mostrou valores maiores em relação aos outros grupos ooforectomizados. Esses resultados foram correspondentes aos achados em relação às células da zona proliferativa, desde que o CG teve os maiores valores e os valores do grupo OVx GS45 foram superiores aos dos grupos OVx 21, OVx GS21 e OVx 45. CONCLUSÃO: Nossos estudos sugerem que a glicosamina pode estimular o crescimento da cartilagem e do osso tibial após a ooforectomia em ratas.