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Braz. j. biol ; 82: e241081, 2022. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1285584


Abstract This study investigated the use of melatonin to arrest the effects of apoptosis in vitrified zebrafish (D. rerio) embryos. Dechorionated embryos at 22-24 somite-stage were divided (n = 60/treatment) into a non-vitrified (Control Group, 0 M melatonin) and vitrified treatments with 0 M (T1), 1 µM (T2) and 1 mM of melatonin (T3). For vitrified treatments, a solution methanol/propylene glycol based was used and the embryos stored in -196 °C for a week. After thaw, survival rate, scanning electron microscopy, expression of anti (bcl-2) and pro-apoptotic (bax/caspase-3) genes, reactive oxygen species (ROS) formation and DNA fragmentation analyses were performed. No live embryos were obtained from vitrified treatments, observing a rapid degeneration immediately after thawing, with the vitelline layer rupture and leakage of its content, followed by breakdown of epithelial cells and melanisation of the tissue. Regarding the apoptotic process, T3 had the highest relative gene expression, for the three genes (P < 0.05) furthermore, T2 had similar expression of pro-apoptotic genes to CG (P < 0.05). ROS formation revealed that CG presented lower percentage of embryo surface area affected (3.80 ± 0.40%) (P < 0.05), in contrast, no differences were found among the other groups. T1 was most significantly (P < 0.05) damaged by DNA fragmentation. The vitrified groups with melatonin had similar damage levels of CG (P > 0.05). The inclusion of 1 µM of melatonin in the vitrifying solution, countered the effects of apoptotic process in post-thaw embryos, suggesting its utility in cryopreserving fish embryos.

Resumo Este estudo investigou o uso da melatonina para conter os efeitos da apoptose em embriões vitrificados de zebrafish (D. rerio). Embriões descorionados no estágio de 22-24 somitos foram divididos (n = 60 / tratamento) em tratamento não vitrificado (Grupo Controle, melatonina 0 M) e tratamentos vitrificados com 0 M (T1), 1 µM (T2) e 1 mM de melatonina (T3). Para os tratamentos vitrificados, utilizou-se uma solução à base de metanol/propilenoglicol e os embriões foram armazenados em -196 °C por uma semana. Após o descongelamento, foram realizadas análises de taxa de sobrevivência, microscopia eletrônica de varredura, expressão dos genes anti (bcl-2) e pró-apoptóticos (bax/caspase-3), formação de espécies reativas de oxigênio (EROS) e análises de fragmentação de DNA. Não foram obtidos embriões vivos a partir dos tratamentos vitrificados, observando uma rápida degeneração imediatamente após o descongelamento, com ruptura da camada vitelina e vazamento de seu conteúdo, seguida de quebra das células epiteliais e melanização do tecido. Em relação ao processo apoptótico. T3 apresentou expressão gênica relativa alta para os três genes (P <0,05), além disso, T2 apresentou expressão semelhante as dos genes pró-apoptóticos de GC (P <0,05). A formação de EROS revelou que GC apresentou menor percentual de área de superfície embrionária afetada (3,80 ± 0,40%) (P <0,05), ao contrário, não foram encontradas diferenças entre os outros grupos. T1 foi mais significativamente (P <0,05) danificado pela fragmentação do DNA. Os grupos vitrificados com melatonina apresentaram níveis de dano semelhantes ao do GC (P> 0,05). A inclusão de 1 µM de melatonina na solução de vitrificação, contrariou os efeitos do processo apoptótico em embriões pós-descongelamento, sugerindo sua utilidade na criopreservação de embriões de peixes.

Animals , Zebrafish , Melatonin/pharmacology , Cryopreservation , Apoptosis
Article in Chinese | WPRIM | ID: wpr-879850


OBJECTIVE@#To study the effect of different melatonin treatment regimens on long-term behavior and white matter damage in neonatal rats with hypoxic-ischemic brain damage (HIBD), and to seek an optimal melatonin treatment regimen.@*METHODS@#Healthy Sprague-Dawley rats, aged 7 days, were randomly divided into four groups: sham-operation, HIBD, single-dose immediate treatment (SDIT), and 7-day continuous treatment (7DCT), with 8 rats in each group. A neonatal rat model of HIBD was prepared according to the classical Rice-Vannucci method. On day 21 after HIBD, the Morris water maze test was used to evaluate spatial learning and memory abilities. On day 70 after HIBD, immunofluorescence assay was used to measure the expression of neuronal nuclear antigen (NeuN) in the cerebral cortex and the hippocampal CA1 region of neonatal rats, and double-label immunofluorescence was used to measure the expression of myelin basic protein (MBP) and neurofilament 200 (NF200) in the corpus striatum and the corpus callosum.@*RESULTS@#The results of the Morris water maze test showed that the SDIT and 7DCT groups had a significantly shorter mean escape latency than the HIBD group, and the 7DCT group had a significantly shorter mean escape latency than the SDIT group (@*CONCLUSIONS@#Both SDIT and 7DCT can improve long-term behavior and reduce white matter damage in neonatal rats with HIBD, and 7DCT is more effective than SDIT.

Animals , Animals, Newborn , Hypoxia-Ischemia, Brain/drug therapy , Melatonin/pharmacology , Rats , Rats, Sprague-Dawley , White Matter
Int. j. morphol ; 38(5): 1455-1462, oct. 2020. tab, graf
Article in English | LILACS | ID: biblio-1134462


SUMMARY: This study aimed to investigate the changes in testis tissue of thioacetamide-induced rats and the effect of melatonin on these changes. Thirty-five male Wistar Albino rats were divided into five groups. Group I; Control (n=7), Group II; Melatonin (Mel) (10 mg/kg) a single dose (i.p)(n=7), Group III; Thioacetamide (TAA) (300 mg/kg) (i.p) 2 times with 24 hour intervals (n=7), Group IV; TAA (300 mg/kg) was administered at 24-hour intervals, afterwards of 10 mg/kg single dose of Mel (n=7), Group V; Mel was administered 10 mg/kg a single dose 24 hours before the administration of TAA (n=7). Testis was evaluated histologically, immunohistochemically (Heat Shock Proteins (HSP) 70 and 90), blood serum testosterone, total antioxidant status(TAS) and total oxidant status(TOS) in tissue. The tissue sections of Group III decreased seminiferous tubule diameters, and germinal epithelium spills were observed. HSP70 and HSP90 expressions were increased. There wasn't a statistically significant change in testosterone levels among the groups. While TAS levels decreased in Group III compared to control, TOS levels didn't change. HSP70 and HSP90 decreased in groups with Mel-treated. Mel was found to have both protective and therapeutic effects. According to our results, the therapeutic effect of Mel in thioacetamide-induced acute testicular injury is greater than its protective effect.

RESUMEN: Este estudio tuvo como objetivo investigar los cambios en el tejido testicular de ratas inducidas por tioacetamida y el efecto de la melatonina en estos cambios. Treinta y cinco ratas macho Wistar Albino se dividieron en cinco grupos. Grupo I; Control (n = 7), Grupo II; Melatonina (Mel) (10 mg / kg) una dosis única (i.p) (n = 7), Grupo III; Tioacetamida (TAA) (300 mg / kg) (i.p) 2 veces con intervalos de 24 horas (n = 7), Grupo IV; TAA (300 mg / kg) se administró a intervalos de 24 horas, luego de una dosis única de 10 mg / kg de Mel (n = 7), Grupo V; Mel recibió 10 mg / kg de una dosis única 24 horas antes de la administración de TAA (n = 7). Los testículos se evaluaron histológicamente, inmunohistoquímicamente (proteínas de choque térmico (PCT) 70 y 90), testosterona en suero sanguíneo, estado antioxidante total (EAT) y estado oxidante total (EOT) en el tejido. En secciones de tejido del Grupo III se observó disminución de los diámetros de los túbulos seminíferos y derrames en el epitelio germinal. Se aumentaron las expresiones HSP70 y HSP90. No hubo un cambio estadísticamente significativo en los niveles de testosterona entre los grupos. Mientras que los niveles de EAT disminuyeron en el Grupo III en comparación con el control, los niveles de EOT no cambiaron. HSP70 y HSP90 disminuyeron en los grupos tratados con Mel. Se descubrió que Mel tenía efectos protectores y terapéuticos. Según nuestros resultados, el efecto terapéutico de Mel en la lesión testicular aguda inducida por tioacetamida es mayor que su efecto protector.

Animals , Male , Rats , Testis/drug effects , Thioacetamide/toxicity , Melatonin/pharmacology , Antioxidants/pharmacology , Enzyme-Linked Immunosorbent Assay , Immunohistochemistry , Rats, Wistar , Heat-Shock Proteins/drug effects , Heat-Shock Proteins/metabolism , Melatonin/administration & dosage , Antioxidants/administration & dosage
Rev. Assoc. Med. Bras. (1992) ; 65(8): 1122-1127, Aug. 2019. tab, graf
Article in English | LILACS | ID: biblio-1041057


SUMMARY Melatonin is known for its effects on both the sleep and reproductive system of mammals. The latter has melatonin receptors type 1 and 2, which act to regulate, among other things, cyclic AMP. Notwithstanding all the literature data, there is still no sound knowledge or a clear understanding of the hormone's action on the physiology of ovarian follicular cells. OBJECTIVE To review and evaluate studies about melatonin action on the ovarian granulosa/theca interna cells from the literature. METHODS The systematic review was carried out according to the PRISMA recommendations. The MEDLINE and Cochrane primary databases were consulted with the use of specific terms. There was no limitation on language or publication year. RESULTS Seven papers about melatonin action on granulosa cells were selected. The following can be attributed to the hormone's effects: a) progesterone increase in culture medium; b) increased estrogen production; c) antagonistic action on estrogen; d) improvement in cell quality resulting in improved embryo and higher pregnancy rates; e) improved cell proliferation via MAPK; f) reduction of free radicals. Nevertheless, there are contrarian papers reporting a reduction in progesterone production. CONCLUSION Melatonin interferes in sex steroid production, boosting progesterone output. Such action may help improve oocyte quality.

RESUMO A melatonina é conhecida por seus efeitos no sono e no sistema reprodutivo dos mamíferos. Este último tem receptores de melatonina tipos 1 e 2, que atuam para regular, entre outras coisas, o AMP cíclico. Apesar de todos os dados da literatura, ainda não há um conhecimento sólido ou uma compreensão clara da ação do hormônio na fisiologia das células foliculares ovarianas. OBJETIVO Revisar e avaliar estudos da ação da melatonina na literatura sobre as células internas da granulosa/teca ovariana. MÉTODOS A revisão sistemática foi realizada de acordo com as recomendações do Prisma. As bases de dados primárias Medline e Cochrane foram consultadas com o uso de termos específicos. Não houve bar na língua ou ano de publicação. RESULTADOS Sete artigos sobre a ação da melatonina nas células da granulosa foram selecionados. O que se segue pode ser atribuído aos efeitos do hormônio: a) aumento de progesterona no meio de cultura; b) aumento da produção de estrogênio; c) ação antagônica no estrogênio; d) melhoria na qualidade celular, resultando em melhor embrião e maiores taxas de gravidez; e) melhor proliferação celular via MAPK; f) redução de radicais livres. No entanto, existem artigos controversos relatando redução na produção de progesterona. CONCLUSÃO A melatonina interfere na produção de esteroides sexuais, aumentando a produção de progesterona. Tal ação pode ajudar a melhorar a qualidade do oócito.

Humans , Female , Pregnancy , Oocytes/drug effects , Ovarian Follicle/drug effects , Melatonin/pharmacology , Oocytes/growth & development , Progesterone/antagonists & inhibitors , Theca Cells/drug effects , Cells, Cultured , Granulosa Cells/drug effects
Int. j. morphol ; 37(2): 428-437, June 2019. tab, graf
Article in English | LILACS | ID: biblio-1002239


Oxidative stress and inflammation are the key players in the development of motor dysfunction post-spinal cord ischemic reperfusion injury (SC-IRI). This study investigated the protective effect of concomitant pre-administration of melatonin and alpha-tocopherol on the early complications (after 48 hours) of spinal cord IRI injury in rats. Melatonin or α-tocopherol were preadministered either individually or in combination for 2 weeks, then rats were exposed SC-IRI. Neurological examinations of the hind limbs and various biochemical markers of oxidative stress and inflammation in the SC tissue were assessed. Solely pre-administration of either melanin or α-tocopherol significantly but partially improved motor and sensory function of the hind limbs mediated by partial decreases in SC levels of MDA, AOPP and PGE2 levels and activities of SOD, partial significant decreases in plasma levels of total nitrate/nitrite and significant increases in AC activity of GSH-Px. However, combination therapy of both drugs resulted in the maximum improvements in all neurological assessments tested and biochemical endpoints. In conclusion, by their synergistic antioxidant and antiinflammatory actions, the combination therapy of melatonin and α-tocopherol alleviates SC-IRI induced paraplegia.

El estrés oxidativo y la inflamación son claves en el desarrollo de la disfunción motora posterior a lesión isquémica de la médula espinal (SC-IRI). Este estudio investigó acerca del efecto protector de la administración previa concomitante de la melatonina y alfa-tocoferol en las complicaciones tempranas (después de 48 horas) de la lesión de IRI de la médula espinal en ratas. La melatonina o el α-tocoferol se administraron individualmente o en combinación durante 2 semanas, luego las ratas fueron expuestas a SC-IRI. Se evaluaron los exámenes neurológicos de las miembros pélvicos y diversos marcadores bioquímicos de estrés oxidativo e inflamación en el tejido subcutáneo. Solo la administración previa de melatonina o α-tocoferol mejoró parcial y significativamente la función motora y sensorial de los miembros pélvicos mediadas por disminuciones parciales en los niveles de SC de los niveles de MDA, AOPP y PGE2 y las actividades de la SOD, disminuciones significativas parciales en los niveles plasmáticos del total nitrato / nitrito y aumentos significativos en la actividad de AC de GSH-Px. Sin embargo, se observaron los mejores resultados durante la combinación de ambos fármacos en todas las evaluaciones neurológicas y en los puntos finales bioquímicos. En conclusión, debido a sus acciones antioxidantes y antiinflamatorias sinérgicas, la terapia de melatonina y α-tocoferol alivia la paraplejía inducida por SC-IRI.

Animals , Rats , Reperfusion Injury/drug therapy , Spinal Cord Ischemia/drug therapy , Melatonin/administration & dosage , Antioxidants/administration & dosage , Paraplegia , Spinal Cord/drug effects , Spinal Cord/pathology , Dinoprostone/blood , Rats, Sprague-Dawley , Oxidative Stress/drug effects , Tocopherols/pharmacology , Melatonin/pharmacology , Nitrites/blood , Antioxidants/pharmacology
J. bras. pneumol ; 45(3): e20170164, 2019. tab, graf
Article in English | LILACS | ID: biblio-1012550


ABSTRACT Objective: To evaluate the pulmonary alterations of animals with Hepatopulmonary Syndrome (HPS) submitted to Biliary Duct Ligature (BDL), as well as the antioxidant effect of Melatonin (MEL). Methods: Sixteen male Wistar rats, divided into four Sham groups: BDL group, Sham + MEL group and BDL + MEL. The pulmonary and hepatic histology, lipoperoxidation and antioxidant activity of lung tissue, alveolar-arterial O2 difference and lung / body weight ratio (%) were evaluated. Results: When comparing the groups, could be observed an increase of vasodilation and pulmonary fibrosis in the BDL group and the reduction of this in relation to the BDL + MEL group. It was also observed significant changes in the activity of catalase, ApCO2, ApO2 in the LBD group when compared to the other groups. Conclusion: The use of MEL has been shown to be effective in reducing vasodilation, fibrosis levels and oxidative stress as well as gas exchange in an experimental HPS model.

RESUMO Objetivo: Avaliar as alterações pulmonares de animais com Síndrome Hepatopulmonar (SHP), submetidos à ligadura de ducto biliar (LDB), bem como o efeito antioxidante da Melatonina (MEL). Métodos: Dezesseis ratos machos da espécie Wistar, divididos em quatro grupos: Sham, Grupo LDB, Grupo Sham + MEL e LDB + MEL. Foram avaliadas a histologia pulmonar e hepática, a lipoperoxidação e atividade antioxidante do tecido pulmonar, diferença álveolo-arterial de O2 e relação peso pulmonar/peso corporal (%). Resultados: Quando comparados os grupos, observamos um aumento da vasodilatação e fibrose pulmonar no grupo LDB e a redução deste em relação ao grupo LDB+MEL. Observamos ainda alterações significativas na atividade da catalase, PaCO2, PaO2 no grupo LBD quando comparado aos demais grupos. Conclusões: A utilização da MEL demonstrou-se eficaz na redução da vasodilatação, níveis de fibrose e estresse oxidativo assim como na troca gasosa em modelo experimental de SHP.

Animals , Male , Hepatopulmonary Syndrome/drug therapy , Lung/drug effects , Melatonin/pharmacology , Antioxidants/pharmacology , Bile Ducts/surgery , Blood Gas Analysis , Lipid Peroxidation/drug effects , Catalase/analysis , Hepatopulmonary Syndrome/physiopathology , Hepatopulmonary Syndrome/pathology , Disease Models, Animal , Arterial Pressure/drug effects , Glutathione Transferase/analysis , Ligation , Liver/drug effects , Liver/pathology
Clinics ; 74: e658, 2019. tab, graf
Article in English | LILACS | ID: biblio-989637


OBJECTIVES Vascular endothelial growth factor (VEGF) and its receptors play important roles in angiogenesis. Melatonin plays an important role in gonadal development; thus, its effect on the reproductive system is evident. We investigated the influence of melatonin on the expression of VEGF, vascular endothelial growth factor receptor-1 (VEGFR1) and vascular endothelial growth factor receptor-2 (VEGFR2), as well as on changes in oxidative stress markers and follicle numbers in rat ovaries. METHODS For this purpose, 45 Wistar rats were separated into the following groups: Group 1, control; Group 2, vehicle; and Group 3, melatonin. Rats in Group 3 were treated with melatonin at 50 mg/kg/day for 30 days. The effects of melatonin on the expression of VEGF, VEGFR1 and VEGFR2 were established by immunohistochemistry analysis. The effects of melatonin on antioxidant enzyme activities were demonstrated by spectrophotometric analysis. RESULTS Based on immunohistochemistry analysis, VEGFR2 was predominantly localized to theca cells in the ovary. Our data indicate that melatonin treatment can significantly increase VEGF and VEGFR1 expression in the ovary ( p <0.05). Additionally, the number of degenerated follicles significantly decreased with melatonin treatment ( p <0.05). Melatonin administration also led to significant increases in antioxidant enzyme levels in the ovary. CONCLUSION Melatonin treatment exerts protective effects on follicles against increased lipid peroxidation through modulating tissue antioxidant enzyme levels. These effects may be related to angiogenesis and antioxidant activities.

Animals , Female , Ovary/drug effects , Neovascularization, Physiologic/drug effects , Vascular Endothelial Growth Factor Receptor-2/drug effects , Vascular Endothelial Growth Factor A/drug effects , Melatonin/pharmacology , Antioxidants/pharmacology , Ovary/enzymology , Ovary/blood supply , Superoxide Dismutase/metabolism , Lipid Peroxidation , Catalase/metabolism , Rats, Wistar , Models, Animal , Malondialdehyde/metabolism , Melatonin/metabolism , Antioxidants/metabolism
Acta cir. bras ; 33(7): 629-640, July 2018. tab, graf
Article in English | LILACS | ID: biblio-949364


Abstract Purpose: To investigate the effect of melatonin on uterine tissue in the ovariectomized rat model. Methods: Fourty Wistar albino rats were divided into four groups for histologic and immunohistochemical examination. The rats were first numbered randomly and then randomly divided into 4 equal groups: control (group 1), torsion (group 2), torsion+detorsion (group 3) and torsion+detorsion+melatonin (group 4) groups. In addition, four Wistar albino rats were used for western blot analysis in each group. And also, malondialdehyde (MDA) levels were measured biochemically in all rats. Results: The histopathological examination of the uterine tissue in rats ovarectomized showed a degeneration in uterine glands, dilation of blood vessels in the internal layer with a thrombosis and bleeding, abnormal nucleuses and vacuolated cytoplasm above and below the nucleus. In torsion group, the apoptotic cells increased in luminal epithelium and gland cells. In the melatonin group showed that the Bcl2 negative effect on the uterine epithelium and did not lead to apoptotic cells. Conclusion: The increase in vascular endothelial growth factor expression resulted in the rearrangement of endothelial cell growth and the induction of angiogenesis.

Animals , Female , Uterus/drug effects , Uterus/pathology , Estrus/drug effects , Genes, bcl-2/drug effects , Vascular Endothelial Growth Factor A/analysis , Melatonin/pharmacology , Antioxidants/pharmacology , Immunohistochemistry , Ovariectomy , Random Allocation , Blotting, Western , Actins/analysis , Vascular Endothelial Growth Factor A/drug effects , Malondialdehyde/analysis
Acta cir. bras ; 33(4): 375-385, Apr. 2018. tab, graf
Article in English | LILACS | ID: biblio-886280


Abstract Purpose: To investigate the effects of melatonin on antioxidant capacity, inflammation and apoptotic cell death (through expression of cleaved-caspase 3) in lung tissue samples of diabetic rats. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups. Group 1 (control group) was made up of healthy rats. Group 2 (diabetes group) received streptozotocin at a dose of 50 mg/kg/day for 5 days.Group 3 (diabetes plus melatonin group) received streptozotocin at a dose of 50 mg/kg/day for 5 days and then they received melatonin at a dose of 20 mg/kg/day between 28thand 35thdays of the study. Results: Tissue MDA and MPO levels were found to be significantly higher in diabetes group compared to control group (p<0.05) whilst administration of melatonin was found to significantly lower this increase down to normal levels (p<0.05). Bronchus associated lymphoid tissue (BALT) was more severe in diabetics whereas administration of melatonin alleviated this hyperplasia. Cleaved caspase 3 activity was severe in hyperplastic BALT in diabetic rats however in lowered down to moderate level when melatonin was administered. Conclusion: The melatonin caused an increase in antioxidant capacity and decreased the expression of cleaved-caspase 3.

Animals , Male , Diabetes Mellitus, Experimental/pathology , Caspase 3/analysis , Pyroptosis/drug effects , Lung/drug effects , Melatonin/pharmacology , Antioxidants/pharmacology , Superoxide Dismutase/analysis , Time Factors , Immunohistochemistry , Lipid Peroxidation , Catalase/analysis , Random Allocation , Reproducibility of Results , Rats, Sprague-Dawley , Streptozocin , Peroxidase/analysis , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/metabolism , Caspase 3/drug effects , Glutathione/analysis , Lung/metabolism , Lung/pathology , Malondialdehyde/analysis
Arq. bras. cardiol ; 110(1): 44-51, Jan. 2018. graf
Article in English | LILACS | ID: biblio-887998


Resumo Background: Melatonin is a neuroendocrine hormone synthesized primarily by the pineal gland that is indicated to effectively prevent myocardial reperfusion injury. It is unclear whether melatonin protects cardiac function from reperfusion injury by modulating intracellular calcium homeostasis. Objective: Demonstrate that melatonin protect against myocardial reperfusion injury through modulating IP3R and SERCA2a to maintain calcium homeostasis via activation of ERK1 in cardiomyocytes. Methods: In vitro experiments were performed using H9C2 cells undergoing simulative hypoxia/reoxygenation (H/R) induction. Expression level of ERK1, IP3R and SERCA2a were assessed by Western Blots. Cardiomyocytes apoptosis was detected by TUNEL. Phalloidin-staining was used to assess alteration of actin filament organization of cardiomyocytes. Fura-2 /AM was used to measure intracellular Ca2+ concentration. Performing in vivo experiments, myocardial expression of IP3R and SERCA2a were detected by immunofluorescence staining using myocardial ischemia/ reperfusion (I/R) model in rats. Results: In vitro results showed that melatonin induces ERK1 activation in cardiomyocytes against H/R which was inhibited by PD98059 (ERK1 inhibitor). The results showed melatonin inhibit apoptosis of cardiomyocytes and improve actin filament organization in cardiomyocytes against H/R, because both could be reversed by PD98059. Melatonin was showed to reduce calcium overload, further to inhibit IP3R expression and promote SERCA2a expression via ERK1 pathway in cardiomyocytes against H/R. Melatonin induced lower IP3R and higher SERCA2a expression in myocardium that were reversed by PD98059. Conclusion: melatonin-induced cardioprotection against reperfusion injury is at least partly through modulation of IP3R and SERCA2a to maintain intracellular calcium homeostasis via activation of ERK1.

Resumo Fundamento: A melatonina é um hormônio neuroendócrino sintetizado principalmente pela glândula pineal que é indicado para prevenir efetivamente a lesão de reperfusão miocárdica. Não está claro se a melatonina protege a função cardíaca da lesão de reperfusão através da modulação da homeostase do cálcio intracelular. Objetivo: Demonstrar que a melatonina protege contra a lesão de reperfusão miocárdica através da modulação de IP3R e SERCA para manter a homeostase de cálcio por meio da ativação de ERK1 em cardiomiócitos. Métodos: Foram realizados experimentos in vitro usando células H9C2 submetidas a indução de hipoxia / reoxigenação simulada (H/R). O nível de expressão de ERK1, IP3R e SERCA foi avaliado por Western Blots. A apoptose de cardiomiócitos foi detectada por TUNEL. A coloração de faloidina foi utilizada para avaliar a alteração da organização de filamentos de actina dos cardiomiócitos. Fura-2 / AM foi utilizado para medir a concentração intracelular de Ca2+. Realizando experiências in vivo, a expressão miocárdica de IP3R e SERCA foi detectada por coloração com imunofluorescência usando modelo de isquemia miocárdica / reperfusão (I/R) em ratos. Resultados: resultados in vitro mostraram que a melatonina induz a ativação de ERK1 em cardiomiócitos contra H/R que foi inibida por PD98059 (inibidor de ERK1). Os resultados mostraram que a melatonina inibe a apoptose dos cardiomiócitos e melhora a organização do filamento de actina em cardiomiócitos contra H/R, pois ambas poderiam ser revertidas pela PD98059. A melatonina mostrou reduzir a sobrecarga de cálcio, além de inibir a expressão de IP3R e promover a expressão de SERCA através da via ERK1 em cardiomiócitos contra H/R. A melatonina induziu menor IP3R e maior expressão de SERCA no miocárdio que foram revertidas pela PD98059. Conclusão: a cardioproteção induzida pela melatonina contra lesão de reperfusão é pelo menos parcialmente através da modulação de IP3R e SERCA para manter a homeostase de cálcio intracelular via ativação de ERK1.

Animals , Male , Rats , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/prevention & control , MAP Kinase Signaling System/drug effects , Myocytes, Cardiac/drug effects , Sarcoplasmic Reticulum Calcium-Transporting ATPases/drug effects , Inositol 1,4,5-Trisphosphate Receptors/drug effects , Melatonin/pharmacology , Myocardial Reperfusion Injury/pathology , Rats, Sprague-Dawley , Myocytes, Cardiac/pathology , Disease Models, Animal , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Inositol 1,4,5-Trisphosphate Receptors/metabolism
Egyptian Journal of Hospital Medicine [The]. 2018; 71 (2): 2498-2504
in English | IMEMR | ID: emr-192489


Background: delirium is an extremely common syndrome in the intensive care unit [ICU]. It is characterized by acute fluctuations and alterations in attention and arousal. Critically ill patients are at particularly high risk, and those that develop delirium are more likely to experience poor clinical outcomes such as prolonged duration of ICU and hospital length of stay, and increased mortality. Melatonin and melatonin agonists [MMA] have the potential to decrease the incidence and severity of delirium

Aim of the study: to review and assess the role of melatonin in several clinical applications in perioperative management, critical care and pain medicine

Conclusion: melatonin reported eight peri-operative outcomes: anxiety; analgesia; sleep quality; oxidative stress; emergence behavior; anesthetic requirements; steal induction; and safety. Evidence-based, multi modal, surgical and anesthetic approaches have reduced morbidity and mortality following surgical procedures

Humans , Melatonin/pharmacology , Anesthesia/adverse effects , Critical Care , Delirium , Perioperative Care
Biol. Res ; 51: 17, 2018. graf
Article in English | LILACS | ID: biblio-950903


BACKGROUND: Improper control on reactive oxygen species (ROS) elimination process and formation of free radicals causes tissue dysfunction. Pineal hormone melatonin is considered a potent regulator of such oxidative damage in different vertebrates. Aim of the current communication is to evaluate the levels of oxidative stress and ROS induced damage, and amelioration of oxidative status through melatonin induced activation of signaling pathways. Hepatocytes were isolated from adult Labeo rohita and exposed to H2O2 at three different doses (12.5, 25 and 50 µM) to observe peroxide induced damage in fish hepatocytes. Melatonin (25, 50 and 100 µg/ml) was administered against the highest dose of H2O2. Enzymatic and non-enzymatic antioxidants such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) was measured spectrophotometrically. Expression level of heat shock proteins (HSP70 and HSP90), HSPs-associated signaling molecules (Akt, ERK, cytosolic and nuclear NFkB), and melatonin receptor was also measured by western blotting analysis. RESULTS: H2O2 induced oxidative stress significantly altered (P < 0.05) MDA and GSH level, SOD and CAT activity, and up regulated HSP70 and HSP90 expression in carp hepatocytes. Signaling proteins exhibited differential modulation as revealed from their expression patterns in H2O2-exposed fish hepatocytes, in comparison with control hepatocytes. Melatonin treatment of H2O2-stressed fish hepatocytes restored basal cellular oxidative status in a dose dependent manner. Melatonin was observed to be inducer of signaling process by modulation of signaling molecules and melatonin receptor. CONCLUSIONS: The results suggest that exogenous melatonin at the concentration of 100 µg/ml is required to improve oxidative status of the H2O2-stressed fish hepatocytes. In H2O2 exposed hepatocytes, melatonin modulates expression of HSP70 and HSP90 that enable the hepatocytes to become stress tolerant and survive by altering the actions of ERK, Akt, cytosolic and nuclear NFkB in the signal transduction pathways. Study also confirms that melatonin could act through melatonin receptor coupled to ERK/Akt signaling pathways. This understanding of the mechanism by which melatonin regulates oxidative status in the stressed hepatocytes may initiate the development of novel strategies for hepatic disease therapy in future.

Animals , Signal Transduction/drug effects , Oxidative Stress/drug effects , Hepatocytes/drug effects , Hydrogen Peroxide/pharmacology , Melatonin/pharmacology , Spectrophotometry , Superoxide Dismutase/drug effects , Catalase/drug effects , Catalase/metabolism , Blotting, Western , NF-kappa B/drug effects , NF-kappa B/metabolism , Reactive Oxygen Species/metabolism , MAP Kinase Signaling System/drug effects , Hepatocytes/metabolism , Proto-Oncogene Proteins c-akt/drug effects , Fishes , Glutathione/drug effects , Glutathione/metabolism , Malondialdehyde/metabolism
ABCD arq. bras. cir. dig ; 31(1): e1352, 2018. tab
Article in English | LILACS | ID: biblio-949203


ABSTRACT Background: Intracellular calcium overload is known to be a precipitating factor of pancreatic cell injury in acute pancreatitis (AP). Intracellular calcium homeostasis depends of Plasmatic Membrane Calcium ATPase (PMCA), Sarcoplasmic Endothelial Reticulum Calcium ATPase 2 (SERCA 2) and the Sodium Calcium Exchanger (NCX1). The antioxidant melatonin (Mel) and Trisulfate Disaccharide (TD) that accelerates NCX1 action could reduce the cell damage determined by the AP. Aim: To evaluate m-RNA expressions of SERCA2 and NCX1 in acute pancreatitis induced by sodium taurocholate in Wistar rats pre-treated with melatonin and/or TD. Methods: Wistar rats were divided in groups: 1) without AP; 2) AP without pre-treatment; 3) AP and Melatonin; 4) AP and TD; 5) AP and Melatonin associated to TD. Pancreatic tissue samples were collected for detection of SERCA2 and NCX1 m-R NA levels by polymerase chain reaction (PCR). Results: Increased m-RNA expression of SERCA2 in the melatonin treated group, without increase of m-RNA expression of the NCX1. The TD did not affect levels of SERCA2 and NCX1 m-RNA expressions. The combined melatonin and TD treatment reduced the m-RNA expression of SERCA2. Conclusions: The effect of melatonin is restricted to increased m-RNA expression of SERCA2. Although TD does not affect gene expression, its action in accelerating calcium exchanger function can explain the slightest expression of SERCA2 m-RNA when associated with Melatonin, perhaps by a joint action of drugs with different and but possibly complementary mechanisms.

RESUMO Racional: A lesão celular da pancreatite aguda (PA) envolve sobrecarga de cálcio, regulada pela atividade da Cálcio ATPase de membrana (PMCA), Cálcio ATPase do Retículo (SERCA2) e pelo Trocador Sódio Cálcio (NCX1). A melatonina (antioxidante) e o Dissacarídeo Trissulfatado (acelerador do NCX1) poderiam reduzir a lesão celular na PA. Objetivo: Avaliar a expressão do RNAm da SERCA2 e NCX1 em modelo animal de pancreatite aguda tratados com melatonina e/ou dissacarídeo trissulfatado (DT). Método: Ratos Wistar foram divididos em grupos: 1) sem pancreatite aguda; 2) com pancreatite aguda por taurocolato; 3) PA e Melatonina; 4) PA e DT; 5) PA e Melatonina com DT. Amostras de tecido foram colhidas para detecção dos níveis de RNAm da SERCA2 e NCX1 por PCR. Resultados: Houve aumento da expressão do RNAm da SERCA2 no grupo com PA tratados com Melatonina, porém sem aumento de expressão do NCX1. O DT não afetou os níveis de SERCA2 e NCX1. O tratamento conjunto com Melatonina e DT diminuiu a expressão da SERCA2. Conclusões: O efeito da Melatonina é restrito ao aumento da expressão da SERCA2. O DT não tem ação na expressão gênica, porém sua ação na aceleração do trocador na retirada do cálcio pode explicar a menor expressão da SERCA2 quando associado à Melatonina, pela ação conjunta de drogas com mecanismos diferentes e possivelmente complementares.

Animals , Male , Rats , Pancreatitis/genetics , RNA, Messenger/biosynthesis , Sodium-Calcium Exchanger/genetics , Cytoprotection/genetics , Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics , Pancreatitis/chemically induced , Taurocholic Acid/administration & dosage , Acute Disease , Rats, Wistar , Disaccharides/pharmacology , Disease Models, Animal , Melatonin/pharmacology
J. appl. oral sci ; 26: e20170470, 2018. graf
Article in English | LILACS, BBO | ID: biblio-954503


Abstract The hypothesis of this study was that the peri-implant bone healing of the group of pinealectomized rats would differ from the control group. The samples were subjected to immunohistochemical, microtomographic (total porosity and connectivity density), and fluorochrome (mineralized surface) analyses. Objectives The goal of this study was to investigate the cellular changes and bone remodeling dynamics along the bone/implant interface in pinealectomized rats. Material and Methods The total of 18 adult male rats (Rattus norvegicus albinus, Wistar) was divided into three groups (n=6): control (CO), pinealectomized without melatonin (PNX) and pinealectomized with melatonin (PNXm). All animals were submitted to the first surgery (pinealectomy), except the CO group. Thirty days after the pinealectomy without melatonin, the second surgery was conducted, in which all animals received an implant in each tibia (36 titanium implants with surface treatment were installed - Implalife® São Paulo, SP, Brazil). By gavage, the rats of the PNX group received the vehicle solution, and the procedure. Results Immunohistochemical analysis for runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OP) and osteocalcin (OC) showed that the bone repair process in the PNXm group was similar to that of the CO group, whereas the PNX group showed a delay. The microtomographic parameters of total porosity [Po(tot)] and bone surface (BS) showed no statistically significant differences, whereas for the connective density (Conn.Dn) a statistical difference was found between the CO and PNXm groups. Fluorochrome analysis of the active mineralized surface showed statistically significant difference between the CO and PNX and between the CO and PNXm groups. Conclusion The absence of the pineal gland impaired the bone repair process during osseointegration, however the daily melatonin replacement was able to restore this response.

Animals , Male , Pineal Gland/surgery , Osseointegration/drug effects , Bone Density Conservation Agents/pharmacology , Bone-Implant Interface , Melatonin/pharmacology , Tibia/drug effects , Tibia/injuries , Tibia/pathology , Titanium , Immunohistochemistry , Osteocalcin/analysis , Reproducibility of Results , Treatment Outcome , Rats, Wistar , Implants, Experimental , Dental Implantation, Endosseous , Alkaline Phosphatase/analysis , Core Binding Factor Alpha 1 Subunit/analysis , Osteopontin/analysis , X-Ray Microtomography , Fluorescent Dyes
IJRM-International Journal of Reproductive Biomedicine. 2017; 15 (7): 403-412
in English | IMEMR | ID: emr-189252


Background: Cyclophosphamide [CP] has been known as an anticancer drug with several side effects on various organs such as a male reproductive system that can cause infertility

Objective: To evaluate the possible combined effects of zinc oxide nanoparticles [nZno] and melatonin [Mel] on sperm parameters and histopathological changes of the testis in CP-treated rats

Materials and Methods: 42 adult male Wistar rats were divided into six groups. GI: control, GII: 60 mg/kg/wk CP, GIII and GIV, 10 mg/kg/wk Mel and 5mg/kg/wk nZno and GV: 5 mg/kg/wk nZno and 10 mg/kg/wk Mel were given 2 hr prior to CP injection, respectively, GVI: 5mg/kg/wk nZno and 10 mg/kg/wk Mel simultaneously. After 8 wk of treatment, rats were sacrificed and testis and epididymis were harvested for further evaluation

Results: The CP-treated group showed significant decreases in the body, testes and epididymis weights and sperm parameters [sperm count, viability, motility] with an increase abnormal sperms when compared with the control [p<0.001], as well as many histological alterations included decreased diameters of seminiferous tubules and Johnsen's Testicular Score [with degeneration, desquamation, multi-nucleated giant cell formation], whereas combined treatment [GV], showed more protective effects on CP-induced reproductive system damage compared with groups III or IV [p<0.001]

Conclusion: These results suggest simultaneous administration of Mel and nZno have more effectively protections against CP-induced reproductive damage than Mel or nZno alone

Animals, Laboratory , Melatonin/pharmacology , Protective Agents , Nanoparticles , Cyclophosphamide/toxicity , Testis/drug effects , Spermatozoa/drug effects , Rats, Wistar
Int. j. morphol ; 34(2): 763-769, June 2016. ilus
Article in English | LILACS | ID: lil-787066


The aim of this study was to evaluate the effects of melatonin healing in a tibial bone defect model in rats by means of histopathological and immunohistochemistry analysis. Twenty one male Wistar albino rats were used in this study. In each animal, bone defects (6 mm length ) were created in the tibias. The animals were divided into three groups. In group 1 control group (rats which tibial defects). Group 2 melatonin (10 mg/kg) + 14 days in the tibial defect group) was administered intraperitoneally to rats. Group 3 melatonin (10 mg/kg) + 28 days in the tibial defect group) was administered intraperitoneally to rats. Histopathological analysis of samples was performed to evaluate the process of osteoblastic activity, matrix formation, trabecular bone formation and myeloid tissue in bone defects. Immunohistochemical and immunoblot analysis demonstrated non-collagenous proteins (osteopontin and osteonectin) differences in tibial bone defects. The expression of osteopontin on tibia was increased by 14 days melatonin treatment. The expression of osteonectin on tibia was dramatically increased by 14 days melatonin treatment.

El objetivo fue evaluar por medio de análisis histopatológico e inmunohistoquímico los efectos cicatrizantes de la melatonina en un modelo de defecto óseo tibial en ratas. Se utilizaron 21 ratas albinas Wistar macho. En cada animal, se crearon defectos óseos en las tibias de 6 mm de longitud. Los animales se dividieron en tres grupos. El Grupo 1 correspondió al grupo control (defectos tibiales sin tratamiento). Al Grupo 2 se administró melatonina por vía intraperitoneal (10 mg/kg) 14 días posteriores al defecto tibial. Al Grupo 3 se administró melatonina por vía intraperitoneal (10 mg/kg) 28 días posteriores al defecto tibial. Se realizó un análisis histopatológico para evaluar los procesos de actividad osteoblástica, formación de matriz, formación de hueso trabecular y tejido mieloide en los defectos óseos. Los análisis inmunohistoquímicos y de inmunotransferencia mostraron diferencias de proteínas no colágenas (osteopontina y osteonectina). La expresión de osteopontina en defectos óseos tibiales se incrementó en el Grupo 2. La expresión de osteonectina en la tibia se incrementó fuertemente bajo el tratamiento con melatonina por 14 días.

Animals , Rats , Melatonin/pharmacology , Tibial Fractures/drug therapy , Tibia/drug effects , Disease Models, Animal , Melatonin/administration & dosage , Osteonectin/drug effects , Osteonectin/metabolism , Osteopontin/drug effects , Osteopontin/metabolism , Rats, Sprague-Dawley , Tibial Fractures/pathology , Tibia/pathology , Wound Healing/drug effects
J. appl. oral sci ; 24(2): 153-161, Mar.-Apr. 2016. graf
Article in English | LILACS | ID: lil-779903


ABSTRACT Objective Biocompatible materials such as interconnected porous hydroxyapatite ceramics (IP-CHA) loaded with osteogenic cells and bioactive agents are part of an evolving concept for overcoming craniofacial defects by use of artificial bone tissue regeneration. Amongst the bioactive agents, melatonin (MEL) and basic fibroblast growth factor (FGF-2) have been independently reported to induce osteoblastic activity. The present in vitro study was undertaken to examine the relationship between these two bioactive agents and their combinatory effects on osteoblastic activity and mineralization in vitro. Material and Methods Mouse preosteoblast cells (MC3T3-E1) were seeded and cultured within cylindrical type of IP-CHA block (ø 4x7 mm) by vacuum-assisted method. The IP-CHA/MC3T3 composites were subjected to FGF-2 and/or MEL. The proliferation assay, alkaline phosphatase enzyme activity (ALP), mRNA expressions of late bone markers, namely Osteocalcin (OCN) and Osteopontin (OPN), and Alizarin Red staining were examined over a period of 7 days. Results FGF-2 mainly enhanced the proliferation of MC3T3-E1 cells within the IP-CHA constructs. MEL mainly induced the mRNA expression of late bone markers (OCN and OPN) and showed increased ALP activity of MC3T3 cells cultured within IP-CHA construct. Moreover, the combination of FGF-2 and MEL showed increased osteogenic activity within the IP-CHA construct in terms of cell proliferation, upregulated expressions of OCN and OPN, increased ALP activity and mineralization with Alizarin Red. The synergy of the proliferative potential of FGF-2 and the differentiation potential of MEL showed increased osteogenic activity in MC3T3-E1 cells cultured within IP-CHA constructs. Conclusion These findings indicate that the combination of FGF-2 and MEL may be utilized with biocompatible materials to attain augmented osteogenic activity and mineralization.

Animals , Mice , Osteoblasts/drug effects , Fibroblast Growth Factor 2/pharmacology , Durapatite/pharmacology , Bone Substitutes/pharmacology , Melatonin/pharmacology , Time Factors , Materials Testing , Calcification, Physiologic/drug effects , Microscopy, Electron, Scanning , Cell Differentiation/drug effects , Cell Survival/drug effects , Cells, Cultured , Reproducibility of Results , Reverse Transcriptase Polymerase Chain Reaction , Cell Proliferation/drug effects , Alkaline Phosphatase/analysis
Arch. endocrinol. metab. (Online) ; 59(5): 391-399, Oct. 2015. graf
Article in English | LILACS | ID: lil-764109


Melatonin referred as the hormone of darkness is mainly secreted by pineal gland, its levels being elevated during night and low during the day. The effects of melatonin on insulin secretion are mediated through the melatonin receptors (MT1 and MT2). It decreases insulin secretion by inhibiting cAMP and cGMP pathways but activates the phospholipaseC/IP3 pathway, which mobilizes Ca2+from organelles and, consequently increases insulin secretion. Both in vivo and in vitro, insulin secretion by the pancreatic islets in a circadian manner, is due to the melatonin action on the melatonin receptors inducing a phase shift in the cells. Melatonin may be involved in the genesis of diabetes as a reduction in melatonin levels and a functional interrelationship between melatonin and insulin was observed in diabetic patients. Evidences from experimental studies proved that melatonin induces production of insulin growth factor and promotes insulin receptor tyrosine phosphorylation. The disturbance of internal circadian system induces glucose intolerance and insulin resistance, which could be restored by melatonin supplementation. Therefore, the presence of melatonin receptors on human pancreatic islets may have an impact on pharmacotherapy of type 2 diabetes.

Animals , Humans , /metabolism , Melatonin/physiology , Circadian Rhythm/physiology , /etiology , Glucose/metabolism , Insulin-Secreting Cells/metabolism , Insulin , Melatonin/pharmacology , Polymorphism, Genetic , Receptors, Melatonin/physiology , Signal Transduction/physiology
Rev. Assoc. Med. Bras. (1992) ; 61(3): 269-274, May-Jun/2015.
Article in English | LILACS | ID: lil-753173


Summary The pineal gland is responsible for producing a hormone called melatonin (MEL), and is accepted as the gland that regulates reproduction in mammals. Prolactin (PRL) also exhibits reproductive activity in animals in response to photoperiod. It is known that the concentrations of PRL are high in the summer and reduced during winter, the opposite of what is seen with melatonin in these seasons. In placental mammals, both prolactin and melatonin affect implantation, which is considered a critical point of pregnancy, since a successful pregnancy requires the development of a synchronous interaction between the endometrium and blastocyst for placental development. It is also known that PRL levels during pregnancy are essential for the maintenance of pregnancy, because this hormone induces the corpus luteum to produce progesterone, in addition to stimulating blastocyst implantation to maintain pregnancy and form the placenta. However, melatonin levels in plasma have also been shown to increase during pregnancy, peaking at the end of this period, which suggests that this hormone plays an important role in the maintenance of pregnancy. Thus, it is clear that treatment with prolactin or melatonin interferes with the processes responsible for the development and maintenance of pregnancy.

Resumo A glândula pineal é responsável pela produção do hormônio melatonina (MEL), sendo aceita como a glândula reguladora da reprodução em mamíferos. A prolactina (PRL) também exibe atividade reprodutiva em animais, em resposta ao fotoperíodo. Sabe-se que as concentrações de PRL são elevadas durante o verão e baixam durante o inverno, ocorrendo o oposto com os níveis do hormônio melatonina nessas estações. Nos mamíferos placentários, tanto a melatonina quanto a prolactina influenciam a implantação, que é considerada o ponto crítico da gravidez, pois o sucesso da gestação requer o desenvolvimento de uma interação sincronizada entre o endométrio e o blastocisto para o desenvolvimento da placenta. Sabe- -se ainda que os níveis de PRL durante a gestação são essenciais para a manutenção da gravidez, pois esse hormônio induz o corpo lúteo a produzir progesterona, além de estimular a implantação do blastocisto, mantendo a prenhez e o desenvolvimento placentário. Em contrapartida, tem-se demonstrado também que os níveis de melatonina no plasma aumentam durante a gestação, atingindo valores elevados no fim desse período, sugerindo que esse hormônio desempenhe um importante papel na manutenção da gestação. Dessa forma, fica claro que o tratamento com prolactina ou melatonina interfere nos processos responsáveis pelo desenvolvimento e pela manutenção da gestação.

Animals , Female , Humans , Pregnancy , Melatonin/pharmacology , Prolactin/pharmacology , Reproduction/drug effects , Blastocyst/physiology , Cell Proliferation/drug effects , Embryo Implantation/drug effects , Melatonin/metabolism , Photoperiod , Pineal Gland/cytology , Pineal Gland/physiology , Prolactin/metabolism , Reproduction/physiology
Arch. endocrinol. metab. (Online) ; 59(1): 66-70, 02/2015. graf
Article in English | LILACS | ID: lil-746441


Objective Obstructive sleep apnea is a common disorder associated with aging and obesity. Apneas cause repeated arousals, intermittent hypoxia, and oxidative stress. Changes in glucolipidic profile occur in apnea patients, independently of obesity. Animal models of sleep apnea induce hyperglycemia. This study aims to evaluate the effect of the antioxidants melatonin and N-acetylcysteine on glucose, triglyceride, and cholesterol levels in animals exposed to intermittent hypoxia. Materials and methods Two groups of Balb/c mice were exposed to intermittent hypoxia (n = 36) or sham intermittent hypoxia (n = 36) for 35 days. The intermittent hypoxia group underwent a total of 480 cycles of 30 seconds reducing the inspired oxygen fraction from 21% to 7 ± 1% followed by 30 seconds of normoxia, during 8 hours daily. Melatonin or N-acetylcysteine were injected intraperitonially daily from day 21 on. Results At day 35, glucose levels were significantly higher in the intermittent hypoxia group than in the control group. The intermittent hypoxia groups receiving N-acetylcysteine and vehicle showed higher glucose levels than the group receiving melatonin. The lipid profile was not affected by intermittent hypoxia or antioxidant administration. Conclusions The present results suggest that melatonin prevents the well-recognized increase in glucose levels that usually follows exposure to intermittent hypoxia. Further exploration of the role of melatonin in sleep apnea is warranted. Arch Endocrinol Metab. 2015;59(1):66-70 .

Animals , Hypoxia/drug therapy , Antioxidants/pharmacology , Hyperglycemia/drug therapy , Melatonin/pharmacology , Sleep Apnea, Obstructive/drug therapy , Acetylcysteine/pharmacology , Hypoxia/blood , Blood Glucose/analysis , Body Weight/drug effects , Cholesterol/blood , Disease Models, Animal , Free Radical Scavengers/pharmacology , Mice, Inbred BALB C , Time Factors , Triglycerides/blood