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1.
Phytochemistry ; 212: 113710, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37178942

RESUMO

Six undescribed C27-phytoecdysteroid derivatives, named superecdysones A-F, and ten known analogs were extracted from the whole plant of Dianthus superbus L. Their structures were identified by extensive spectroscopy, mass spectrometric methods, chemical transformations, chiral HPLC analysis, and the single-crystal X-ray diffraction analysis. Superecdysones A and B possess a tetrahydrofuran ring in the side chain and superecdysones C-E are rare phytoecdysones containing a (R)-lactic acid moiety, whereas superecdysone F is an uncommon B-ring-modified ecdysone. Notably, based on the variable temperature (from 333 K to 253 K) NMR experiments of superecdysone C, the missing carbon signals were visible at 253 K and assigned. The neuroinflammatory bioassay of all compounds were evaluated, and 22-acetyl-2-deoxyecdysone, 2-deoxy-20-hydroxyecdysone, 20-hydroxyecdysone, ecdysterone-22-O-benzoate, 20-hydroxyecdysone-20,22-O-R-ethylidene, and acetonide derivative 20-hydroxyecdysterone-20, 22-acetonide significantly suppressed the LPS-induced nitric oxide generation in microglia cells (BV-2), with IC50 values ranging from 6.9 to 23.0 µM. Structure-activity relationships were also discussed. Molecular docking simulations of the active compounds confirmed the possible mechanism of action against neuroinflammations. Furthermore, none compounds showed cytotoxicity against HepG2 and MCF-7. It is the first report about the occurrence and anti-neuroinflammatory activity of the phytoecdysteroids in the genus Dianthus. Our findings demonstrated that ecdysteroids may be used as potential anti-inflammatory drugs.


Assuntos
Dianthus , Dianthus/química , Ecdisterona/farmacologia , Simulação de Acoplamento Molecular , Doenças Neuroinflamatórias , Ecdisteroides/farmacologia
2.
J Back Musculoskelet Rehabil ; 35(6): 1311-1319, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35599469

RESUMO

BACKGROUND: Non-specific low back pain (NS-LBP) is a serious public health problem. Tai Chi is promising in reducing the risk of falls and alleviating symptoms in this population. OBJECTIVE: To investigate the effect of Tai Chi on gait and dynamic balance in elderly women with NS-LBP. METHODS: 20 women (age > 65 yr.) with NS-LBP were randomly assigned to a Tai Chi group (n= 10) or a control group (n= 10). The Tai Chi group practiced Tai Chi exercise 3 times a week for 6 weeks. Each session lasted 60 minutes. Pain, spatiotemporal gait features and dynamic balancing capacity were assessed at 0 and 6 weeks. RESULTS: Compared to the control group at 6 weeks, the Tai Chi group had a significant decrease in VAS (p= 0.027) and stride width (p= 0.019), significant improvement in gait velocity, stride length (p< 0.001). Regarding dynamic balance capacity, the Tai Chi group had significant improvements in anterior (Left: p= 0.001; Right: p= 0.038), postero-lateral (Left: p< 0.001; Right: p= 0.038), and postero-medial (Left: p= 0.015; Right: p= 0.018). CONCLUSION: 6-week Tai Chi can relieve pain and improve gait and dynamic balance in elderly women with NS-LBP, which suggests Tai Chi could be a promising rehabilitation intervention to reduce the risk of falls in this population.


Assuntos
Dor Lombar , Tai Chi Chuan , Humanos , Feminino , Idoso , Equilíbrio Postural , Dor Lombar/terapia , Marcha , Acidentes por Quedas/prevenção & controle , Dor nas Costas
3.
J Sports Med Phys Fitness ; 62(11): 1568-1575, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35179334

RESUMO

BACKGROUND: The prevalence of essential hypertension increases consistently among middle-aged and older adults in China. Aims of this study are to explore the impact of Tai Chi and square dance, which are popular in China, on antihypertensive effects and cardiovascular disease risk factors in patients with essential hypertension. METHODS: Patients with essential hypertension were randomly assigned to either a Tai Chi group, a square dance group or a control group. Blood pressure, cardiorespiratory fitness, and cardiovascular disease risk factors were measured at baseline and at the end of the 12-week intervention. The duration and frequency of both intervention exercises were 60 minutes per session, and 5 sessions per week. RESULTS: A total of 144 participants (59.89±6.85 years, 34.72% male) completed the study. The repeated-measures analysis of variance demonstrated a significant effect of time on BMI, systolic and diastolic blood pressure, and cardiorespiratory fitness in patients with essential hypertension (P<0.05), whereas no significant effect was observed on waist-to-hip ratio and body fat percentage (P>0.05). Post hoc analyses showed that only intervention groups had significant differences in blood pressure and cardiorespiratory fitness compared to the control group, while Tai Chi had greater effect sizes than square dance. CONCLUSIONS: Both Tai Chi and square dance can promote cardiorespiratory fitness and reduce BMI and blood pressure among patients with essential hypertension, whereas there was no significant difference between the two exercises. However, both Tai Chi and square dance were ineffective in reducing some of the cardiovascular disease risk factors.


Assuntos
Doenças Cardiovasculares , Dança , Tai Chi Chuan , Pessoa de Meia-Idade , Humanos , Masculino , Idoso , Feminino , Hipertensão Essencial/terapia , Anti-Hipertensivos , Doenças Cardiovasculares/prevenção & controle , Fatores de Risco de Doenças Cardíacas
4.
Inflammation ; 45(1): 212-221, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34467464

RESUMO

Dihydrotanshinone (DIH) is an extract of Salvia miltiorrhiza Bunge. It has been reported that DIH could regulate NF-κB signaling pathway. The aim of this study was to investigate whether DIH could protect mice from lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. In this study, sixty mice were randomly divided into five groups, one group as blank control group, the second group as LPS control group, and the last three groups were pre-injected with different doses of DIH and then inhaled LPS for experimental comparison. After 12 h of LPS treatment, the wet-dry ratio, histopathlogical changes, and myeloperoxidase (MPO) activity of lungs were measured. In addition, ELISA kits were used to measure the levels of TNF-α and IL-1ß inflammatory cytokines in bronchoalveolar lavage fluids (BALF), and western blot analysis was used to measure the activity of NF-κB signaling pathway. The results demonstrated that DIH could effectively reduce pulmonary edema, MPO activity, and improve the lung histopathlogical changes. Furthermore, DIH suppressed the levels of inflammatory cytokines in BALF, such as TNF-α and IL-1ß. In addition, DIH could also downregulate the activity of NF-κB signaling pathway. We also found that DIH dose-dependently increased the expression of LXRα. In addition, DIH could inhibit LPS-induced IL-8 production and NF-κB activation in A549 cells. And the inhibitory effects were reversed by LXRα inhibitor geranylgeranyl pyrophosphate (GGPP). Therefore, we speculate that DIH regulates LPS-induced ALI in mice by increasing LXRα expression, which subsequently inhibiting NF-κB signaling pathway.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Anti-Inflamatórios/farmacologia , Furanos/farmacologia , Receptores X do Fígado/metabolismo , Fenantrenos/farmacologia , Extratos Vegetais/farmacologia , Quinonas/farmacologia , Regulação para Cima/efeitos dos fármacos , Lesão Pulmonar Aguda/etiologia , Lesão Pulmonar Aguda/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Biomarcadores/metabolismo , Furanos/uso terapêutico , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/metabolismo , Fenantrenos/uso terapêutico , Extratos Vegetais/uso terapêutico , Quinonas/uso terapêutico , Distribuição Aleatória , Transdução de Sinais
5.
BMC Genomics ; 20(1): 776, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31653200

RESUMO

BACKGROUND: Aphid (Macrosiphoniella sanbourni) stress drastically influences the yield and quality of chrysanthemum, and grafting has been widely used to improve tolerance to biotic and abiotic stresses. However, the effect of grafting on the resistance of chrysanthemum to aphids remains unclear. Therefore, we used the RNA-Seq platform to perform a de novo transcriptome assembly to analyze the self-rooted grafted chrysanthemum (Chrysanthemum morifolium T. 'Hangbaiju') and the grafted Artermisia-chrysanthemum (grafted onto Artemisia scoparia W.) transcription response to aphid stress. RESULTS: The results showed that there were 1337 differentially expressed genes (DEGs), among which 680 were upregulated and 667 were downregulated, in the grafted Artemisia-chrysanthemum compared to the self-rooted grafted chrysanthemum. These genes were mainly involved in sucrose metabolism, the biosynthesis of secondary metabolites, the plant hormone signaling pathway and the plant-to-pathogen pathway. KEGG and GO enrichment analyses revealed the coordinated upregulation of these genes from numerous functional categories related to aphid stress responses. In addition, we determined the physiological indicators of chrysanthemum under aphid stress, and the results were consistent with the molecular sequencing results. All evidence indicated that grafting chrysanthemum onto A. scoparia W. upregulated aphid stress responses in chrysanthemum. CONCLUSION: In summary, our study presents a genome-wide transcript profile of the self-rooted grafted chrysanthemum and the grafted Artemisia-chrysanthemum and provides insights into the molecular mechanisms of C. morifolium T. in response to aphid infestation. These data will contribute to further studies of aphid tolerance and the exploration of new candidate genes for chrysanthemum molecular breeding.


Assuntos
Afídeos/fisiologia , Artemisia/citologia , Chrysanthemum/genética , Chrysanthemum/parasitologia , Perfilação da Expressão Gênica , Horticultura , Interações Hospedeiro-Parasita/genética , Animais , Chrysanthemum/citologia , Chrysanthemum/fisiologia , Anotação de Sequência Molecular , Estresse Fisiológico/genética
6.
Oncol Rep ; 39(3): 1475-1484, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29328482

RESUMO

Cytisine, a quinolizidine alkaloid, is one of the major bioactive components found in the small tree Sophora Alopecuraides L., and is a traditional Chinese medicine that is used for treating hepatitis and liver cancer. In the 1960s, quinolizidine alkaloids were reported to exhibit inhibitory effects on tumour cell proliferation in several types of cancer cells. However, few studies have investigated the effect of cytisine on liver cancer. Our team confirmed that cytisine induced apoptosis in HepG2 cells via a mitochondrial pathway. The primary aim of the present study was to evaluate the endoplasmic reticulum (ER) stress caused by calcium overload in cytisine­induced apoptosis in HepG2 cells and the molecular mechanisms of this phenomenon. In addition, the present study was undertaken to evaluate the expression of α7­nAChR when apoptosis was induced by cytisine in HepG2 cells. In the present study, transmission electron microscopy was used to observe the morphological appearance of HepG2 cells. The apoptosis of the cells with cytoplasmic vacuolization was significant under electron microscopy. Apoptotic bodies, the expansion of the ER, and swelling of mitochondria were observed in the HepG2 cells after cytisine treatment. Flow cytometric analysis demonstrated that the apoptosis rate of HepG2 cells was upregulated. In addition, the intracellular calcium concentration was detected by laser confocal fluorescence microscopy. The laser confocal fluorescence microscopy showed that the calcium concentration was increased in a dose­dependent manner. The activity of caspase­4 was evaluated by an enzyme­linked analyser, and the expression levels of CHOP, JNK, p­JNK and α7­nAChR were assessed via western blot analysis. In the present study, we observed that cytisine induced ER stress­inducing factors and CHOP and p­JNK1/2 protein expression, and it increased the JNK protein expression in the HepG2 cells. Furthermore, α7­nAChR protein expression was promoted in a dose­dependent manner after cytisine treatment. These findings suggest that cytisine induced the ER stress­mediated apoptotic pathway via activation of CHOP, JNK and caspase­4 in HepG2 cells, and cytisine is a potential new target compound for nAchRs (nicotinic acetylcholine receptors) to treat liver cancer.


Assuntos
Alcaloides/farmacologia , Cálcio/metabolismo , Carcinoma Hepatocelular/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Neoplasias Hepáticas/patologia , Apoptose/efeitos dos fármacos , Azocinas/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Mitocôndrias/efeitos dos fármacos , Quinolizinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Células Tumorais Cultivadas
7.
Oncol Rep ; 37(1): 357-367, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27878299

RESUMO

The 'ethnodrug' Capparis spinosa L. has several pharmacological activities. First, it was found in previous experiments that an ethyl acetate extract of Capparis spinosa L. (CSE) exhibited antioxidant activity. In order to further research this finding, the present study investigate the blood biochemical indices, injury, energy metabolism, oxidative damage and mitochondrial membrane potential (Δψm) level of cardiac cells to study the effect of CSE on doxorubicin-induced cardiac toxicity. CSE had protective effects on the cardiac toxic effect of doxorubicin, and decreased the activity of lactic dehydrogenase (LDH) and creatine kinase (CK). CSE increased the ability of myocardial tissue to scavenge free radicals, inhibited lipid peroxidation, increased recovery activity of antioxidant enzymes, adjusted the energy metabolism of myocardial tissue, inhibited the generation of a large number of ROS in the cells, raised the level of Δψm, and improved the metabolism of free radicals. CSE demonstrated protective effects on doxorubicin-induced myocardial damage. Second, the quaternary ammonium hydroxide of Capparis spinosa L. (CSQAH) was found to possess antitumor activity, such as antiproliferative and apoptosis-induced effects on HepG2 cells. We investigated the regulatory mechanism of HepG2 apoptosis induced by CSQAH. Laser scanning confocal microscope and Fluo-3/AM staining were utilized to detect the Ca2+ concentration in the HepG2 cells. A microplate reader was used to measure the changes in Ca2+-Mg2+-ATP enzyme. Then, flow cytometry was applied to analyze the activity of ROS and the expression levels of Bcl-2 and Bax. As a result, different concentrations of CSQAH increased the concentration of Ca2+ in the cytoplasm in a dosage-dependent manner. CSQAH decreased the Ca2+­Mg2+­ATPase activity in the HepG2 cells. The levels of ROS in the CSQAH groups were significantly higher than the level in the control group. Flow cytometric analysis showed that the Bcl-2 expression levels in the CSQAH-treated groups were downregulated, while Bax expression levels were upregulated, and the effects were dosage-dependent. The regulatory mechanism of HepG2 cell apoptosis induced by CSQAH involved the increase in Ca2+ concentration and ROS levels, a decrease in Ca2+-Mg2+-ATPase activity in the HepG2 cells, and downregulation of anti-apoptotic Bcl-2 expression, and upregulation of apoptotic Bax expression. In summary, the present study demonstrated the antioxidant and antitumor activities of CSE which may suppress tumor growth and alleviate the side-effects of DOX, which may facilitate tumor treatment in a dual manner.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Capparis/química , Doxorrubicina/efeitos adversos , Animais , Apoptose/efeitos dos fármacos , ATPase de Ca(2+) e Mg(2+)/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Feminino , Células Hep G2/efeitos dos fármacos , Humanos , Masculino , Camundongos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Substâncias Protetoras/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Proteína X Associada a bcl-2/metabolismo
8.
Transplantation ; 100(8): 1683-91, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27362308

RESUMO

BACKGROUND: The dual role of B cells as drivers and suppressors of the immune responses have underscored the need to trace the fate of B cells recognizing donor major histocompatibility complex class I and class II after allograft transplantation. METHODS: In this study, we used donor class II tetramers to trace the fate of I-E-specific B cells after immunization with BALB/c spleen cells or cardiac transplantation, in naive or sensitized C57BL/6 recipients. We combined this approach with genetic lineage tracing of memory B cells in activation-induced cytidine deaminase regulated Cre transgenic mice crossed to the ROSA26-enhanced yellow fluorescent protein reporter mice to track endogenous I-E-specific memory B cell generation. RESULTS: Immunization with BALB/c splenocytes or heart transplantation induced an expansion and differentiation of I-E-specific B cells into germinal center B cells, whereas BALB/c heart transplantation into sensitized recipients induced the preferential differentiation into antibody-secreting cells. A 10.8-fold increase in the frequency of I-E-specific memory B cells was observed by day 42 postimmunization. Treatment with CTLA4-Ig starting on day 0 or day 7 postimmunization abrogated I-E-specific memory B cell generation and sensitized humoral responses, but not if treatment commenced on day 14. CONCLUSIONS: The majority of donor-specific memory B cells are generated between days 7 and 14 postimmunization, thus revealing a flexible timeframe whereby delayed CTLA4-Ig administration can inhibit sensitization and the generation of memory graft-reactive B cells.


Assuntos
Abatacepte/administração & dosagem , Linfócitos B/efeitos dos fármacos , Linhagem da Célula , Proliferação de Células/efeitos dos fármacos , Rejeição de Enxerto/prevenção & controle , Transplante de Coração/efeitos adversos , Antígenos de Histocompatibilidade Classe II/imunologia , Memória Imunológica , Imunossupressores/administração & dosagem , Ativação Linfocitária/efeitos dos fármacos , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Rastreamento de Células/métodos , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Modelos Animais de Doenças , Esquema de Medicação , Genótipo , Rejeição de Enxerto/sangue , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/efeitos dos fármacos , Antígenos de Histocompatibilidade Classe II/sangue , Integrases/genética , Proteínas Luminescentes/biossíntese , Proteínas Luminescentes/genética , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , RNA não Traduzido/genética , Fatores de Tempo
9.
JPEN J Parenter Enteral Nutr ; 40(6): 820-6, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-25690346

RESUMO

BACKGROUND: Inadequate nutrition may contribute to adverse neurodevelopmental and growth outcomes in very low birth weight (VLBW) infants. MATERIALS AND METHODS: A retrospective cohort study was conducted of infants born weighing <1250 g between 2009 and 2010 in a tertiary neonatal intensive care unit. The aim was to investigate whether there was a correlation between the amount of amino acid and calories received in the first 4 weeks of life and neurodevelopment and growth at 2 years. RESULTS: Parenteral amino acid intake in week 2 of life correlated with higher language and motor scores on the 2-year Bayley Scales of Infant and Toddler Development Third Edition (Bayley III). Conversely, higher total amino acid intake during week 1 of life (≥1.5 g/kg/d) was associated with a shorter duration of hospitalization, shorter intensive care stay, fewer days receiving mechanical ventilation, fewer days receiving supplemental oxygen, and a lower incidence of chronic lung disease (CLD). Higher caloric intake in the first 4 weeks correlated strongly with shorter duration of hospitalization, shorter intensive care stay, fewer days on the ventilator, and fewer days receiving supplemental oxygen. In patients with CLD, week 1 and 2 parenteral and total amino acid intake correlated with higher cognitive and motor scores on the Bayley III at 2 years old. Weeks 1-4 amino acid and calorie intake correlated with fewer days on the ventilator, fewer days of supplemental oxygen, and fewer days of hospitalization. CONCLUSION: Amino acid intake within the first weeks of life correlated positively with neurodevelopmental outcomes at 2 years, and patients with CLD were found to be particularly at risk. Caloric intake may affect protein accretion.


Assuntos
Aminoácidos/administração & dosagem , Ingestão de Energia , Recém-Nascido de muito Baixo Peso/crescimento & desenvolvimento , Transtornos do Neurodesenvolvimento/prevenção & controle , Atividades Cotidianas , Peso ao Nascer , Cognição , Feminino , Seguimentos , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Tempo de Internação , Pneumopatias/prevenção & controle , Masculino , Transtornos Motores/prevenção & controle , Sistema Nervoso/crescimento & desenvolvimento , Nutrição Parenteral , Respiração Artificial , Estudos Retrospectivos , Resultado do Tratamento
10.
J Am Coll Nutr ; 34(3): 224-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25757396

RESUMO

The influence of micronization on improving the phytoestrogenic effects of wheat bran was studied. Wheat bran samples were prepared by ball milling, and an animal experiment was carried out by feeding 8-month-old female rats wheat bran. The effect of wheat bran samples on serum estradiol (E2) and progesterone (P) levels of female 8-month-old rats was investigated. The wheat bran with a median diameter of 392.1 µm was micronized to 91.1 and 9.7 µm in median diameter by dry milling and wet milling for 5 hours, respectively. Microscopic observation and X-ray diffraction revealed more potential damage from wet milling than dry milling on the crystal structure of wheat bran granules. Almost all particles were dissolved and there was no obvious crystal peak in the 5-hour wet-milled wheat bran. The serum E2 and P levels of the 8-month-old rats fed wet-milled bran were increased significantly, 2.2 times higher than that of the same aged control group. The experimental results indicated that wet milling could destroy the crystal structure of wheat bran granules and improve the phytoestrogenic effects of wheat bran.


Assuntos
Fibras na Dieta/farmacologia , Manipulação de Alimentos/métodos , Fitoestrógenos/farmacologia , Animais , Cristalização , Fibras na Dieta/análise , Estradiol/sangue , Feminino , Tamanho da Partícula , Progesterona/sangue , Ratos , Ratos Sprague-Dawley , Difração de Raios X
11.
Exp Ther Med ; 8(4): 1201-1204, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25187824

RESUMO

The aim of the present study was to investigate the therapeutic effects of water-soluble extracts of Banxiaxiexin decoction, a classical traditional Chinese medicine formulation, on BALB/c mice with experimentally induced ulcerative colitis (UC). Water-soluble extracts of Banxiaxiexin decoction were intragastrically administered to BALB/c mice with oxazolone (OXA)-induced colitis. Sulfasalazine (SASP) was administered intragastrically to OXA-treated mice to establish the SASP group (positive control). Following drug administration, the disease activity index (DAI) and the histopathological inflammation score were recorded. In addition, the expression levels of interleukin (IL)-5 and IL-13 mRNA in the colonic tissue were determined by fluorescent quantitative polymerase chain reaction. The DAI and histopathological inflammation score of the model group were significantly greater compared with those of the control group, and the mRNA expression levels of IL-5 and IL-13 in the colonic tissue were also significantly higher in the model group compared with those in the control group. The intragastric administration of water-soluble extracts of Banxiaxiexin decoction significantly lowered the DAI and histopathological inflammation score. The mRNA expression levels of IL-5 and IL-13 in the colonic tissue were also significantly lowered. The therapeutic effect of Banxiaxiexin decoction was found to be comparable to that of SASP. In conclusion, the results from the present study demonstrate that water-soluble extracts of the traditional Chinese medicine formulation Banxiaxiexin decoction have a therapeutic effect on BALB/c mice with OXA-induced colitis.

12.
Eur J Pharmacol ; 549(1-3): 117-23, 2006 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-16987513

RESUMO

Intermedin is a novel member of the calcitonin/calcitonin gene-related peptide (CGRP) family peptide, which has vasodilatory and hypotensive actions identical to those of adrenomedullin and CGRP. Cleavage sites located between 2 basic amino acids at Arg93-Arg94 result in the production of prepro-intermedin95-147, namely intermedin1-53. The bioactive action of intermedin1-53 and its physiological significance are unclear. In this work, we aimed to explore the effects of intermedin1-53 on acute myocardial injury induced by isoproterenol. Myocardial ischemia injury in rats was induced by subcutaneous injection of a high dose of isoproterenol, and the therapeutic effect of intermedin1-53 was observed. Plasma lactate dehydrogenase activity, myocardial and plasma malondialdehyde content were higher in the isoproterenol group than that in controls. Isoproterenol-treated rats showed lower maximal rate of increase and decrease of left-ventricle pressure development (+/-left-ventricle dp/dtmax) and higher left-ventricle end-diastolic pressure (all P<0.01), which suggested severe heart failure and myocardial injury. Semi-quantitative RT-PCR analysis showed that the gene expression of calcitonin receptor-like receptor and receptor-activity-modifying protein (RAMP)1, RAMP2 and RAMP3 in ventricular myocardia were up-regulated by 79% (P<0.01), 48% (P<0.01), 31% (P<0.05) and 130% (P<0.01), respectively, compared with controls. In myocardial sarcolemmal membranes, the maximum binding capacity for [125I]-intermedin1-53 was increased by 118% (P<0.01) in the isoproterenol group compared with controls. Rats treated with low dosage intermedin1-53 (5 nmol/kg/day, 2 days) showed 21% (P<0.05) higher myocardial cAMP content, 18% and 31% higher+left-ventricle dp/dtmax and -left-ventricle dp/dtmax respectively, 288% lower left-ventricle end-diastolic pressure (all P<0.01), and attenuated myocardial lactate dehydrogenase leakage and malondialdehyde formation (all P<0.01). Treatment with high dosage intermedin1-53 (20 nmol/kg/day, 2 days) gave better results than that with low dosage intermedin1-53. These results suggest that the intermedin receptor system was up-regulated in isoproterenol-induced myocardial ischemic injury and intermedin1-53 might play a pivotal cardioprotective role in such injury.


Assuntos
Adrenomedulina/farmacologia , Isoproterenol/toxicidade , Infarto do Miocárdio/prevenção & controle , Neuropeptídeos/farmacologia , Fragmentos de Peptídeos/farmacologia , Adrenomedulina/química , Adrenomedulina/metabolismo , Animais , Proteína Semelhante a Receptor de Calcitonina , AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Expressão Gênica/efeitos dos fármacos , Injeções Subcutâneas , Peptídeos e Proteínas de Sinalização Intracelular/genética , Radioisótopos do Iodo , Isoproterenol/administração & dosagem , L-Lactato Desidrogenase/sangue , Masculino , Malondialdeído/sangue , Malondialdeído/metabolismo , Proteínas de Membrana/genética , Infarto do Miocárdio/induzido quimicamente , Infarto do Miocárdio/fisiopatologia , Miocárdio/metabolismo , Miocárdio/patologia , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Fragmentos de Peptídeos/metabolismo , Ligação Proteica/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Proteína 2 Modificadora da Atividade de Receptores , Proteína 3 Modificadora da Atividade de Receptores , Proteínas Modificadoras da Atividade de Receptores , Receptores da Calcitonina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sarcolema/efeitos dos fármacos , Sarcolema/metabolismo
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