Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.216
Filtrar
1.
Med Hypotheses ; 131: 109314, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31443750

RESUMO

Metabolic targeting of liver 5-aminolevulinate synthase (5-ALAS) by inhibition of heme utilisation by tryptophan (Trp) 2,3-dioxygenase (TDO) or the use of tryptophan is proposed as a therapy of acute hepatic porphyrias. 5-ALAS, the rate-limiting enzyme of heme biosynthesis, is under negative feedback control by a small regulatory heme pool in the hepatic cytosol. Acute porphyric attacks, precipitated by fasting, certain hormones and some drugs, involve induction of 5-ALAS secondarily to depletion of the above pool, and the resultant elevation of 5-ALA levels initiates the abdominal and neurological symptoms of attacks. By utilising the regulatory heme, cytosolic TDO undermines the feedback control, thus allowing 5-ALAS induction to occur, e.g. upon glucocorticoid induction of TDO during fasting (starvation) and exogenous glucocorticoid administration. Currently, glucose therapy is the preferred strategy for reversing moderate attacks induced by fasting (calorie restriction), with more severe attacks being treated by intravenous heme preparations. Reversal of fasting-induced attacks by glucose is explained by the previously demonstrated reversal of increased heme utilisation by TDO. Inhibitors of this utilisation are therefore potential therapeutic targets in acute attacks and also for maintenance of a symptomless state. Existing TDO inhibitors other than glucose include allopurinol, nicotinamide and recently developed potent inhibitors such as LM10 used in cancer therapy. Based on studies in rats, the hypothesis predicts that the safety or otherwise of drugs in the hepatic porphyrias is determined by their ability to inhibit TDO utilisation of heme under basal conditions or after glucocorticoid induction or heme activation of TDO, in parallel with reciprocal changes in 5-ALAS induction. Tryptophan is also proposed as a potential therapy of acute attacks either alone or as an adjunct to the recently proposed 5-ALAS1 gene silencing. Trp increases heme biosynthesis by enhancing 5-ALA dehydratase activity and, based on a Trp-5-ALA model presented herein, Trp offers several advantages over heme therapy, namely rapid conversion of 5-ALA into heme, a greatly enhanced heme availability, a near complete inhibition of 5-ALAS induction, assumed rapid clearance of 5-ALA and hence accelerated resolution of symptoms of attacks, and finally provision of the neuroprotective metabolite kynurenic acid to neutralise the neurological symptoms. The hypothesis also addresses heme regulation in species lacking the TDO free apoenzyme and its glucocorticoid induction mechanism and proposes detailed assessment of heme biosynthesis in these species. Detailed proposals for testing the hypothesis are presented.


Assuntos
5-Aminolevulinato Sintetase/antagonistas & inibidores , Inibidores Enzimáticos/uso terapêutico , Heme/metabolismo , Terapia de Alvo Molecular , Porfirias Hepáticas/tratamento farmacológico , Triptofano Oxigenase/antagonistas & inibidores , Triptofano/uso terapêutico , 5-Aminolevulinato Sintetase/genética , Alopurinol/farmacologia , Alopurinol/uso terapêutico , Animais , Indução Enzimática/efeitos dos fármacos , Jejum/metabolismo , Retroalimentação Fisiológica , Inativação Gênica , Glucose/metabolismo , Glucose/uso terapêutico , Cobaias , Heme/uso terapêutico , Humanos , Cinurenina/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Modelos Biológicos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/fisiologia , Porfirias Hepáticas/induzido quimicamente , Porfirias Hepáticas/genética , Porfirias Hepáticas/metabolismo , Roedores , Especificidade da Espécie , Triptofano/efeitos adversos , Triptofano/farmacologia
2.
Mol Med Rep ; 20(3): 2101-2110, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31257518

RESUMO

Ischemia­reperfusion injury (IRI) is a notable cause of tissue damage during surgical procedures and a major risk factor in graft dysfunction in liver transplantation. Livers obtained from donors after circulatory death (DCD) are prone to IRI and toll­like receptor 4 (TLR4) serves a prominent role in the inflammatory response associated with DCD liver IRI. The present study was designed to investigate whether TAK242, a specific TLR4 inhibitor, improves hepatic IRI following a DCD graft and to investigate its underlying protective mechanisms. Male Sprague­Dawley rats were randomized into 4 groups: Control, TAK242, DCD and DCD+TAK242 groups. Rats were pretreated with TAK242 or its vehicle for 30 min, then the livers were harvested without warm ischemia (control group and TAK242 group) or with warm ischemia in situ for 30 min. The livers were stored in cold University of Wisconsin solution for 24 h and subsequently perfused for 60 min with an isolated perfused rat liver system. Rat liver injury was evaluated thereafter. When compared with the DCD group, DCD livers with TAK242 pretreatment displayed significantly improved hepatic tissue injury and less tissue necrosis (P<0.05). Compared with DCD livers, mechanistic experiments revealed that TAK242 pretreatment alleviated mitochondrial dysfunction, reduced reactive oxygen species and malondialdehyde levels and inhibited apoptosis. Additionally, TAK242 significantly inhibited the IRI­associated inflammatory response, indicated by the decreased expression of TLR4, interleukin (IL)­1ß, IL­6 and cyclooxygenase 2 at the mRNA and protein levels (P<0.05). TAK242 ameliorates DCD liver IRI via suppressing the TLR4 signaling pathway in rats. The results of the present study have revealed that TAK242 pretreatment harbors a potential benefit for liver transplantation.


Assuntos
Anti-Inflamatórios/farmacologia , Fígado/efeitos dos fármacos , Preservação de Órgãos/métodos , Traumatismo por Reperfusão/imunologia , Sulfonamidas/farmacologia , Receptor 4 Toll-Like/antagonistas & inibidores , Adenosina/farmacologia , Alopurinol/farmacologia , Animais , Glutationa/farmacologia , Insulina/farmacologia , Fígado/imunologia , Fígado/patologia , Fígado/ultraestrutura , Transplante de Fígado , Masculino , Soluções para Preservação de Órgãos/farmacologia , Rafinose/farmacologia , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/imunologia , Isquemia Quente
3.
Molecules ; 24(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340570

RESUMO

As a traditional natural medicine for treating many kinds of diseases, Gnetum parvifolium showed apparent inhibition on xanthine oxidase (XO). In this study, ultrafiltration combined with liquid chromatography-mass spectrometry (LC-MS) is used for the screening of XO inhibitors from Gnetum parvifolium. Their antioxidation, XO inhibition, and enzymic kinetic parameters are also determined. Finally, piceatannol (1), rhaponiticin (2), resveratrol (3), and isorhapontigenin (4) are screened out and identified as XO inhibitors from the extract of Gnetum parvifolium. Four inhibitors show better inhibition than allopurinol and good radical scavenging abilities. However, the antioxidant activities are weaker than ascorbic acid. The kinetic parameters illustrate the inhibition mode of XO by piceatannol is competitive type, while the inhibition modes for rhaponiticin, resveratrol and isorhapontigenin are uncompetitive types. In order to evaluate the difference among samples obtained in China, the amounts of four inhibitors and related activities in 20 samples are assessed and analyzed by partial least squares analysis. The results indicate piceatannol contribute the highest coefficients in three kinds of activities. Based on these findings, more comprehensive research on pharmaceutical and biochemical activities of these four XO inhibitors could be conducted in future.


Assuntos
Gnetum/química , Resveratrol/isolamento & purificação , Estilbenos/isolamento & purificação , Xantina Oxidase/antagonistas & inibidores , Alopurinol/farmacologia , Compostos de Bifenilo/antagonistas & inibidores , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Depuradores de Radicais Livres/isolamento & purificação , Depuradores de Radicais Livres/farmacologia , Ensaios de Triagem em Larga Escala , Cinética , Análise dos Mínimos Quadrados , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Resveratrol/farmacologia , Estilbenos/farmacologia , Ultrafiltração , Xantina Oxidase/metabolismo
5.
Regul Toxicol Pharmacol ; 107: 104400, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31152858

RESUMO

Fipronil (FPN) can induce oxidative tissue damage and may be contemplated as an apoptosis inducer. Our aim is to investigate the possible hepatoprotective roles of garlic or allopurinol (ALP) against fipronil subacute toxicity. Thirty-six mature male albino rats were randomly divided into six groups; the first group was saved as control (C), the 2nd (G) was orally intubated with 500 mg/kg aqueous garlic extract, and the 3rd (A) received 150 mg/L allopurinol in their drinking water. The 4th group (F) was administered 13.277 mg/kg fipronil by gavage, while the 5th (G + F) and 6th (A + F) groups received the same doses of garlic and allopurinol, respectively two hours before fipronil intoxication. Our results revealed that FPN significantly increased the hepatic malondialdehyde, protein carbonyl levels, and the enzymatic activities of superoxide dismutase, catalase, glutathione peroxidase, and xanthine oxidase, but it decreased glutathione-S-transferase compared to the control group. Moreover, FPN exhibited significant up-regulation in the hepatic pro-apoptotic (Bax) and caspase-3 genes expression, down-regulation in the anti-apoptotic (Bcl-2) mRNA gene expression and induced DNA fragmentation. Surprisingly, garlic or allopurinol co-treatment ameliorated the hepatic lipid peroxidation, antioxidants disruption, and apoptosis induced by FPN. In conclusion, garlic and allopurinol relieved the oxidative injury and reduced the fipronil-induced apoptosis probably by improving the tissue antioxidant defense system.


Assuntos
Alopurinol/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Alho , Inseticidas/toxicidade , Extratos Vegetais/uso terapêutico , Substâncias Protetoras/uso terapêutico , Pirazóis/toxicidade , Alopurinol/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspase 3/genética , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Glutationa/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Oxirredutases/metabolismo , Extratos Vegetais/farmacologia , Raízes de Plantas , Substâncias Protetoras/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ratos
6.
Int J Mol Sci ; 20(11)2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31159151

RESUMO

Quercetin is an abundant flavonoid in nature and is used in several dietary supplements. Although quercetin is extensively metabolized by human enzymes and the colonic microflora, we have only few data regarding the pharmacokinetic interactions of its metabolites. Therefore, we investigated the interaction of human and microbial metabolites of quercetin with the xanthine oxidase enzyme. Inhibitory effects of five conjugates and 23 microbial metabolites were examined with 6-mercaptopurine and xanthine substrates (both at 5 µM), employing allopurinol as a positive control. Quercetin-3'-sulfate, isorhamnetin, tamarixetin, and pyrogallol proved to be strong inhibitors of xanthine oxidase. Sulfate and methyl conjugates were similarly strong inhibitors of both 6-mercaptopurine and xanthine oxidations (IC50 = 0.2-0.7 µM); however, pyrogallol inhibited xanthine oxidation (IC50 = 1.8 µM) with higher potency vs. 6-MP oxidation (IC50 = 10.1 µM). Sulfate and methyl conjugates were approximately ten-fold stronger inhibitors (IC50 = 0.2-0.6 µM) of 6-mercaptopurine oxidation than allopurinol (IC50 = 7.0 µM), and induced more potent inhibition compared to quercetin (IC50 = 1.4 µM). These observations highlight that some quercetin metabolites can exert similar or even a stronger inhibitory effect on xanthine oxidase than the parent compound, which may lead to the development of quercetin-drug interactions (e.g., with 6-mercaptopurin or azathioprine).


Assuntos
Quercetina/análogos & derivados , Quercetina/farmacologia , Xantina Oxidase/antagonistas & inibidores , Alopurinol/química , Alopurinol/farmacologia , Catálise , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Oxirredução , Ligação Proteica , Quercetina/química , Quercetina/metabolismo , Relação Estrutura-Atividade , Xantina/química , Xantina/farmacologia
7.
Acta Cir Bras ; 34(3): e201900306, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30892392

RESUMO

PURPOSE: To investigate the effects of allopurinol administration on osteoinductive reaction and bone development with graft material. METHODS: Thirty-six Wistar albino rats were divided into 3 groups. In the control group, calvarial bone defect was only created without any treatment. In the Defect + Graft group, allograft treatment was performed by forming 8 mm calvarial bone defect. In the Defect + Graft + Allopurinol group, alloplastic bone graft was placed in the calvarial bone defect and then, allopurinol (50 mg/kg/day) treatment was intraperitoneally applied for 28 days. RESULTS: Histopathological examination revealed inflammation, congestion in the vessels, and an increase in osteoclast cells in the defect area. We also observed that new osteocyte cells, increase in connective tissue fibers, and new bone trabeculae. Osteopontin expression was positive in osteoblast cells and lacunated osteocyte cells were located in the periphery of the new bone trabeculae. Osteopontin expression was also positive in osteoblasts and osteocytes cells of new bone trabeculae in the graft site. CONCLUSION: It has been shown that allopurinol treatment in rat calvaria defects may induce osteoblastic activity, matrix development, mature bone cell formation and new bone formation when used with autogenous grafts.


Assuntos
Alopurinol/farmacologia , Regeneração Óssea/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Crânio/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Animais , Autoenxertos , Modelos Animais de Doenças , Ratos , Ratos Wistar , Crânio/lesões
8.
Biochem Biophys Res Commun ; 508(2): 494-498, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30503500

RESUMO

With co-treatment of potassium oxonate (PO) and xanthine sodium salt (XSS), a zebrafish larva model of acute hyperuricemia has been constructed for the first time. The results show PO 200 µM + XSS 10 µM, PO 300 µM + XSS 15 µM, and PO 400 µM + XSS 20 µM can significantly increase the level of uric acid in the zebrafish larvae (P < 0.05), the concentrations as described above can be used to construct the zebrafish larvae model of acute hyperuricemia. At the same time, treatment of allopurinol (APL, one of the hyperuricemia drugs) at 2000 µM (P < 0.001) and treatment of anserine (ASE) at 200 µM (P < 0.05) could significantly decrease the level of uric acid in the model group which received PO 200 µM + XSS 10 µM, which demonstrate that such model could offer a new robust approach for high-throughput screening of food and drugs with uric acid-lowering activity.


Assuntos
Modelos Animais de Doenças , Ensaios de Triagem em Larga Escala/métodos , Hiperuricemia/tratamento farmacológico , Ácido Úrico/metabolismo , Alopurinol/farmacologia , Animais , Anserina/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Hiperuricemia/induzido quimicamente , Larva , Ácido Oxônico , Xantina , Peixe-Zebra
9.
Transplantation ; 103(2): 344-352, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30557272

RESUMO

BACKGROUND: For islet transplantation, pancreas preservation in University of Wisconsin (UW) solution is associated with disadvantages, such as collagenase inhibition, resulting in poor islet yield and islets with poor viability. In this study, we evaluated a novel preservation solution, the extracellular-type c-Jun N-terminal kinase (JNK) inhibitor-containing (EJ) solution. METHODS: The EJ solution has high sodium-low potassium composition with low viscosity compared to UW solution. Moreover, EJ solution contains a recently developed JNK inhibitor from our laboratory. RESULTS: We first compared the performance of EJ solution with that of UW solution. Islet yield before and after purification was significantly higher in the EJ group than in the UW group. Second, we compared the performance of EJ solution with that of EJ solution without the JNK inhibitor (EJ-J solution). After pancreas preservation in EJ solution, JNK activity was maintained at a relatively low level during islet isolation. Islet yield before and after purification was significantly higher in the EJ group than in the EJ-J group. After islet transplantation into streptozotocin-induced diabetic mice, blood glucose levels reached the normoglycemic range in 61.5% and 7.7% of diabetic mice in the EJ and EJ-J groups, respectively. Moreover, EJ solution exhibited reduced inhibition of collagenase digestion compared with UW solution. CONCLUSIONS: Advantages of EJ solution over UW solution were inhibition of JNK activity and reduced collagenase inhibition. EJ solution may therefore be more suitable for islet isolation than UW solution.


Assuntos
Ilhotas Pancreáticas/citologia , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Soluções para Preservação de Órgãos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Adenosina/farmacologia , Alopurinol/farmacologia , Animais , Glicemia/análise , Separação Celular , Feminino , Glutationa/farmacologia , Insulina/farmacologia , Transplante das Ilhotas Pancreáticas , Camundongos , Rafinose/farmacologia , Suínos
10.
Transplantation ; 103(2): 363-370, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30422952

RESUMO

BACKGROUND: Donation after circulatory death (DCD) liver grafts are known to be predisposed to primary nonfunction and ischemic cholangiopathy. Many DCD grafts are discarded because of older donor age or long warm ischemia times. Thus, it is critical to improve the quality of DCD liver grafts. Here, we have tested whether an enriched oxygen carrier added to the preservation solution can prolong graft survival and reduce biliary damage. METHODS: We assessed the adenosine triphosphate (ATP) content decay of mouse liver grafts after cold ischemia, warm ischemia, and combined warm+cold ischemia. In addition, we used a rat model of liver transplantation to compare survival of DCD grafts preserved in high-oxygen solution (preoxygenated perfluorocarbon [PFC] + University of Wisconsin [UW] solution) versus lower oxygen solution (preoxygenated UW solution). RESULTS: Adenosine triphosphate levels under UW preservation fall to less than 10% after 30 minutes of warm ischemia. Preoxygenated UW solution with PFC reached a significantly higher PaO2. After 45 minutes of warm ischemia in oxygenated UW + PFC solution, grafts showed 63% higher levels of ATP (P = 0.011). In addition, this was associated with better preservation of morphology when compared to grafts stored in standard UW solution. Animals that received DCD grafts preserved in higher oxygenation solution showed improved survival: 4 out of 6 animals survived long-term whereas all control group animals died within 24 hours. CONCLUSIONS: The additional oxygen provided by PFC during static cold preservation of DCD livers can better sustain ATP levels, and thereby reduce the severity of ischemic tissue damage. PFC-based preservation solution extends the tolerance to warm ischemia, and may reduce the rate of ischemic cholangiopathy.


Assuntos
Trifosfato de Adenosina/metabolismo , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Fígado , Soluções para Preservação de Órgãos/farmacologia , Oxigênio/farmacologia , Adenosina/farmacologia , Alopurinol/farmacologia , Animais , Isquemia Fria , Fluorcarbonetos/farmacologia , Glutationa/farmacologia , Insulina/farmacologia , Masculino , Preservação de Órgãos , Rafinose/farmacologia , Ratos , Ratos Endogâmicos Lew , Isquemia Quente
11.
Transplant Proc ; 50(10): 3822-3830, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30577274

RESUMO

Deceased donor kidneys are exposed to cold ischemic insult which makes them particularly susceptible to the effects of cold ischemic injury during hypothermic preservation resulting in high rates of delayed graft function. Bone morphogenetic protein-7 (BMP-7) is a valuable reagent in the field of tissue regeneration and preservation under ischemic conditions. Following these insights, we investigated the effect of recombinant human BMP-7 (rhBMP-7) on graft preservation during cold ischemia. The study was conducted on an experimental model of kidney cold ischemia in rats. Kidneys were perfused with University of Wisconsin (UW) saline solution, rhBMP-7, or rhBMP-7 + UW, and exposed to cold ischemia for 6, 12, and 24 hours. In tubular epithelial cells of kidneys perfused with rhBMP-7 and rhBMP-7+UW solution, the expression of BMP-7 and E-cadherin was observed after 24 hours of cold ischemia. In kidneys not perfused with rhBMP-7, high expression of transforming growth factor-ß and α-smooth muscle actin was found. Also, in kidneys perfused with rhBMP-7 solution, statistically higher levels of Smad1, Smad5, and Smad8 messenger RNA expressions were proven. BMP-7 maintains the morphology of kidney tissue better than UW solution during 24 hours of cold ischemia. BMP-7 prevents epithelial to mesenchymal transformation and consequently maintains epithelial phenotype of tubular cells.


Assuntos
Proteína Morfogenética Óssea 7/farmacocinética , Isquemia Fria/efeitos adversos , Soluções para Preservação de Órgãos/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Adenosina/farmacologia , Alopurinol/farmacologia , Animais , Função Retardada do Enxerto/prevenção & controle , Glutationa/farmacologia , Insulina/farmacologia , Transplante de Rim/métodos , Masculino , Rafinose/farmacologia , Ratos
12.
Nitric Oxide ; 81: 57-66, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30393129

RESUMO

Renal transplantation is the preferred treatment for end-stage renal disease. Currently, there is a large gap between the supply and demand for transplantable kidneys. The use of sub-optimal grafts obtained via donation after cardiac death (DCD) is on the rise. While static cold storage (SCS) in University of Wisconsin (UW) solution on ice (4°C) is the clinical standard of care for renal graft preservation, cold storage has been associated with negative graft outcomes. The alternative, normothermic machine perfusion, involves mechanical perfusion of the organ at physiological or normothermic temperature (37°C) and this technique is expensive, complicated and globally inaccessible. As such, simpler alternatives are of interest. Preliminary results revealed that UW solution is more protective at 21°C than 37°C and subnormothermic preservation is of interest because it may facilitate the use of existing solutions while preventing cold injury. We have previously shown that SCS in UW solution supplemented with mitochondria-targeted H2S donor AP39 improves renal graft outcomes. As such, it was hypothesized subnormothermic preservation at 21°C with AP39 will also improve renal outcomes. Using an in vitro model of hypoxia and reoxygenation, we found that treating porcine tubular epithelial cells with UW+5 µM AP39 during 18 h hypoxia at 21°C significantly increased renal tubular epithelial cell viability after 24 h of reoxygenation at 37°C compared to UW alone. Also, AP39-supplemented UW solution was significantly more cytoprotective during hypoxia at 21°C than hypoxia at 37°C, regardless of AP39 concentration. Using an ex vivo DCD organ preservation model, we found that DCD porcine kidneys stored for 24 h in UW+200 nM AP39 at 21°C showed significantly lower tissue necrosis than DCD porcine kidneys preserved using SCS in UW solution, the clinical standard of care. Overall, our findings suggest that exogenous H2S supplementation improves the viability of the gold standard organ preservation solution, UW solution, for subnormothermic preservation at 21°C.


Assuntos
Sulfeto de Hidrogênio/farmacologia , Rim/citologia , Soluções para Preservação de Órgãos/farmacologia , Preservação de Órgãos/métodos , Traumatismo por Reperfusão/prevenção & controle , Adenosina/farmacologia , Alopurinol/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citoproteção , Células Epiteliais/efeitos dos fármacos , Glutationa/farmacologia , Insulina/farmacologia , Transplante de Rim , Compostos Organofosforados/farmacologia , Perfusão , Rafinose/farmacologia , Suínos , Temperatura Ambiente , Tionas/farmacologia
13.
Ther Adv Cardiovasc Dis ; 12(12): 341-349, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30295166

RESUMO

BACKGROUND:: The aim of this study was to evaluate the effects of the antioxidant allopurinol and ischemic post-conditioning on the deleterious effects of ischemia followed by reperfusion (I/R) in a standardized model of ischemia involving infra-renal aortic occlusion in rats. METHODS:: The animals were randomly divided into five groups: (A) animals not subjected to ischemia; (B) animals subjected to 2 h of ischemia and reperfusion only once; (C) animals given an allopurinol dose by gavage, then subjected to 2 h of ischemia and reperfusion only once; (D) animals subjected to 2 h of ischemia and post-conditioning and (E) animals that received allopurinol, then subjected to 2 h of ischemia and post-conditioning. The blood samples and small intestine segments were harvested for analysis after 3 days. RESULTS:: The protective effects of the use of allopurinol and ischemic post-conditioning were observed by measuring aspartate aminotransferase, alanine aminotransferase and lactate levels. The benefits of post-conditioning were evident from the total antioxidant capacity and creatinine levels, but these could not ascertain any positive effects of allopurinol. The histological analysis of mesentery revealed that both methods were effective in minimizing the harmful effects of the ischemia and reperfusion process. CONCLUSION:: Individual protocols significantly reduced I/R systemic injuries, but no additional protection was observed when the two strategies were combined.


Assuntos
Alopurinol/farmacologia , Antioxidantes/farmacologia , Aorta Abdominal/cirurgia , Pós-Condicionamento Isquêmico/métodos , Extremidade Inferior/irrigação sanguínea , Traumatismo por Reperfusão/prevenção & controle , Animais , Biomarcadores/sangue , Modelos Animais de Doenças , Feminino , Ratos Wistar , Fluxo Sanguíneo Regional , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia
14.
PLoS One ; 13(10): e0205758, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30321229

RESUMO

The white color in the larval integument of the silkworm Bombyx mori is considered the result of uric acid accumulation in its epidermal cells. Larvae of the eri silkworm Samia ricini (Lepidoptera; Saturniidae) also have a white and opaque integument, but little is known about its coloration mechanism. In this study, we first performed a feeding assay of S. ricini larvae using allopurinol, an inhibitor of xanthine oxidase, which catalyzes the degradation of xanthine to uric acid. This treatment induced a clear translucent integument phenotype, indicating that the larval color of S. ricini is also determined by uric acid accumulation. Next, to investigate the genetic basis that controls uric acid accumulation in S. ricini larvae, we isolated and characterized the S. ricini homolog of mammalian biogenesis of lysosome-related organelles complex 1, subunit 2 (BLOS2), which is known to play a crucial role in urate granule biosynthesis. We created a transcription activator-like effector nuclease (TALEN)-mediated gene knockout of S. ricini BLOS2 (SrBLOS2) and succeeded in establishing SrBLOS2 knockout strains (SrBLOS2KO). SrBLOS2KO mutants exhibited a translucent larval integument phenotype and lacked uric acid in the epidermis, as also observed in allopurinol-fed larvae. In addition, electron microscopy revealed that urate granules were rarely observed in the epidermis of SrBLOS2KO larvae, whereas abundant granules were found in the epidermis of wild-type larvae. These results clearly demonstrated that larval S. ricini accumulates uric acid as urate granules in the epidermis and that the genetic basis that controls uric acid accumulation is evolutionarily conserved in S. ricini and B. mori.


Assuntos
Mariposas/metabolismo , Ácido Úrico/metabolismo , Alopurinol/farmacologia , Animais , Cor , DNA/genética , Epiderme/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Larva/efeitos dos fármacos , Larva/metabolismo , Larva/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Mariposas/efeitos dos fármacos , Mariposas/genética , Mariposas/ultraestrutura , Filogenia , Análise de Sequência de DNA , Xantina/metabolismo , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/metabolismo
15.
Free Radic Biol Med ; 129: 364-371, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30312761

RESUMO

Generation of superoxide by xanthine oxidase can be stimulated under ischemic and aberrant calcium homeostasis. Because patients and mice with Duchenne muscular dystrophy (DMD) suffer from ischemia and excessive calcium influx, we tested the hypothesis that xanthine oxidase activity is elevated and contributes to disease pathology. Xanthine oxidase activity was measured by urinary isoxanthopterin in DMD patients at rest and in response to exercise. Urinary isoxanthopterin/creatinine was elevated compared to age-matched controls and Becker muscular dystrophy (BMD) patients. Concentrations were also increased after a six minute walk test in ambulatory patients. We also measured urinary isoxanthopterin in wildtype mice and a number of dystrophic mouse models; the DMD mouse model (mdx), mdx mice overexpressing a variety of transgenic miniaturized and chimeric skeletal muscle-specific dystrophins and utrophin and the ß-sarcoglycan deficient (Scgb-/-) mouse which represents type 2E human limb-girdle muscular dystrophy. Mdx and Scgb-/-mice had greater urinary isoxanthopterin/creatinine than wildtype mice while mdx mice expressing dystrophin or utrophin linking the extracellular matrix to the actin cytoskeleton were not different than wildtype. We also measured higher levels of urinary ortho-tyrosine in humans and mice deficient for dystrophin to confirm elevated oxidative stress. Surprisingly, mdx had lower xanthine oxidase protein levels and higher mRNA in gastrocnemius muscle compared to wildtype mice, however, the enzymatic activity of skeletal muscle xanthine oxidase was elevated above wildtype and a transgenic rescued mdx mouse (DysΔMTB-mdx). Downhill treadmill running also caused significant increases in mdx urinary isoxanthopterin that was prevented with the xanthine oxidase inhibitor allopurinol. Similarly, in vitro eccentric contraction-induced force drop of mdx muscle was attenuated by the allopurinol metabolite, oxypurinol. Together, our data suggests hyper-activity of xanthine oxidase in DMD, identifies xanthine oxidase activity as a contributing factor in eccentric contraction-induced force drop of dystrophin-deficient skeletal muscle and highlights the potential of isoxanthopterin as a noninvasive biomarker in DMD.


Assuntos
Distrofina/deficiência , Distrofia Muscular Animal/enzimologia , Distrofia Muscular de Duchenne/enzimologia , Xantina Oxidase/urina , Xantopterina/urina , Adolescente , Alopurinol/farmacologia , Animais , Biomarcadores/urina , Estudos de Casos e Controles , Creatinina/urina , Distrofina/genética , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos mdx , Contração Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/enzimologia , Músculo Esquelético/fisiopatologia , Distrofia Muscular Animal/tratamento farmacológico , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/fisiopatologia , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatologia , Oxipurinol/farmacologia , Sarcoglicanas/deficiência , Sarcoglicanas/genética , Tirosina/urina , Utrofina/deficiência , Utrofina/genética , Xantina Oxidase/genética , Adulto Jovem
16.
Hypertension ; 72(4): 971-978, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30354714

RESUMO

Integrating functional and molecular levels, we investigated the effects of maternal treatment with a xanthine oxidase inhibitor on the programming of cardiac dysfunction in adult offspring using an established rat model of hypoxic pregnancy. Female Wistar rats were divided into normoxic or hypoxic (13% O2) pregnancy±maternal allopurinol treatment (30 mg kg-1 d-1). At 4 months, hearts were isolated from 1 male per litter per outcome variable to determine cardiac function and responses to ischemia-reperfusion in a Langendorff preparation. Sympathetic dominance, perfusate CK (creatine kinase) and LDH (lactate dehydrogenase) and the cardiac protein expression of the ß1-adrenergic receptor, the M2 Ach receptor (muscarinic type-2 acetylcholine receptor), and the SERCA2a (sarcoplasmic reticulum Ca2+ ATPase 2a) were determined. Relative to controls, offspring from hypoxic pregnancy showed elevated left ventricular end diastolic pressure (+34.7%), enhanced contractility (dP/dtmax, +41.6%), reduced coronary flow rate (-21%) and an impaired recovery to ischemia-reperfusion (left ventricular diastolic pressure, area under the curve recovery -19.1%; all P<0.05). Increased sympathetic reactivity (heart rate, +755.5%; left ventricular diastolic pressure, +418.9%) contributed to the enhanced myocardial contractility ( P<0.05). Perfusate CK (+431%) and LDH (+251.3%) and the cardiac expression of SERCA2a (+71.4%) were also elevated ( P<0.05), further linking molecular markers of cardiac stress and injury to dysfunction. Maternal allopurinol restored all functional and molecular indices of cardiac pathology. The data support a link between xanthine oxidase-derived oxidative stress in hypoxic pregnancy and cardiac dysfunction in the adult offspring, providing a target for early intervention in the developmental programming of heart disease.


Assuntos
Alopurinol/farmacologia , Insuficiência Cardíaca , Hipóxia , Contração Miocárdica/fisiologia , Complicações na Gravidez , Sistema Nervoso Simpático , Animais , Inibidores Enzimáticos/farmacologia , Feminino , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/prevenção & controle , Testes de Função Cardíaca , Hipóxia/tratamento farmacológico , Hipóxia/metabolismo , Masculino , Estresse Oxidativo , Gravidez , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/metabolismo , Ratos , Receptor Muscarínico M2/metabolismo , Receptores Adrenérgicos beta/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Sistema Nervoso Simpático/metabolismo , Sistema Nervoso Simpático/fisiopatologia , Xantina Oxidase/antagonistas & inibidores
17.
Int J Parasitol Drugs Drug Resist ; 8(3): 403-410, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30173105

RESUMO

Leishmania infantum is one of the causative agents of visceral leishmaniasis (VL), a widespread, life-threatening disease. This parasite is responsible for the majority of human VL cases in Brazil, the Middle East, China, Central Asia and the Mediterranean basin. Its main reservoir are domestic dogs which, similar to human patients, may develop severe visceral disease and die if not treated. The drug allopurinol is used for the long-term maintenance of dogs with canine leishmaniasis. Following our report of allopurinol resistance in treated relapsed dogs, we investigated the mechanisms and markers of resistance to this drug. Whole genome sequencing (WGS) of clinical resistant and susceptible strains, and laboratory induced resistant parasites, was carried out in order to detect genetic changes associated with resistance. Significant gene copy number variation (CNV) was found between resistant and susceptible isolates at several loci, including a locus on chromosome 30 containing the genes LinJ.30.3550 through LinJ.30.3580. A reduction in copy number for LinJ.30.3560, encoding the S-adenosylmethionine synthetase (METK) gene, was found in two resistant clinical isolates and four induced resistant clonal strains. Using quantitative real time PCR, this reduction in METK copy number was also found in three additional resistant clinical isolates. Furthermore, inhibition of S-adenosylmethionine synthetase encoded by the METK gene in allopurinol susceptible strains resulted in increased allopurinol resistance, confirming its role in resistance to allopurinol. In conclusion, this study identified genetic changes associated with L. infantum resistance to allopurinol and the reduction in METK copy number identified may serve as a marker for resistance in dogs, and reduced protein activity correlated with increased allopurinol resistance.


Assuntos
Alopurinol/farmacologia , Variações do Número de Cópias de DNA/efeitos dos fármacos , Resistência a Medicamentos/genética , Dosagem de Genes/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Leishmania infantum/genética , Metionina Adenosiltransferase/genética , Animais , Doenças do Cão/tratamento farmacológico , Cães , Humanos , Leishmania infantum/enzimologia , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Leishmaniose/veterinária , Leishmaniose Visceral/tratamento farmacológico , Reação em Cadeia da Polimerase em Tempo Real , Sequenciamento Completo do Genoma
18.
Pharmacol Res ; 137: 64-75, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30248460

RESUMO

Excess fructose consumption causes high prevalence of metabolic syndrome and inflammatory liver diseases. The aim of the current study was to investigate the therapeutic effects and underlying molecular mechanisms of curcumin and allopurinol in high fructose-induced hepatic inflammation. Male Sprague-Dawley rats were supplied with standard rat chow and drinking water containing 10% (w/v) fructose for consecutive 12 weeks. Curcumin (15, 30 and 60 mg/kg) and allopurinol (5 mg/kg) were administered to rats via oral gavage daily from Week 7 to 12. For in vitro experiments, curcumin (2.5 µM) and allopurinol (100 µM) were treated to 5 mM fructose-exposed Buffalo rat liver cell line (BRL-3 A) and human hepatoblastoma cell line (HepG2), respectively. The data from these animal and hepatocyte models showed that curcumin and allopurinol ameliorated fructose-induced metabolic symptom, especially hepatic inflammation in rats. Interestingly, down-regulation of microRNA-200a (miR-200a) was screened out in livers of fructose-fed rats and then validated in fructose-exposed BRL-3 A and HepG2 cells. Fructose-induced miR-200a low-expression was identified as a negative mediator of thioredoxin interacting protein (TXNIP) by direct targeting of 3'UTR-rTXNIP, subsequently activating the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome in BRL-3 A cells. Curcumin, as well as allopurinol, notably up-regulated miR-200a expression, accordingly, down-regulated TXNIP and inhibited NLRP3 inflammasome activation in fructose-fed rat livers and fructose-exposed BRL-3 A and HepG2 cells. Taken together, this study firstly identified miR-200a as a biomarker of fructose-induced hepatic inflammation, and revealed the hepatoprotection of curcumin and allopurinol via up-regulating miR-200a-mediated TXNIP/NLRP3 inflammasome pathway.


Assuntos
Alopurinol/farmacologia , Proteínas de Transporte/metabolismo , Curcumina/farmacologia , MicroRNAs/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Substâncias Protetoras/farmacologia , Animais , Proteínas de Ciclo Celular , Linhagem Celular , Frutose , Humanos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Ratos Sprague-Dawley
19.
BMC Nephrol ; 19(1): 244, 2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30241504

RESUMO

BACKGROUND: Sodium nitrite (NaNO2) causes vasodilation, presumably by enzymatic conversion to nitric oxide (NO). Several enzymes with nitrite reducing capabilities have been discovered in vitro, but their relative importance in vivo has not been investigated. We aimed to examine the effects of NaNO2 on blood pressure, fractional sodium excretion (FENa), free water clearance (CH2O) and GFR, after pre-inhibition of xanthine oxidase, carbonic anhydrase, and angiotensin-converting enzyme. The latter as an approach to upregulate endothelial NO synthase activity. METHODS: In a double-blinded, placebo-controlled, crossover study, 16 healthy subjects were treated, in a randomized order, with placebo, allopurinol 150 mg twice daily (TD), enalapril 5 mg TD, or acetazolamide 250 mg TD. After 4 days of treatment and standardized diet, the subjects were examined at our lab. During intravenous infusion of 240 µg NaNO2/kg/hour for 2 h, we measured changes in brachial and central blood pressure (BP), plasma cyclic guanosine monophosphate (P-cGMP), plasma and urine osmolality, GFR by 51Cr-EDTA clearance, FENa and urinary excretion rate of cGMP (U-cGMP) and nitrite and nitrate (U-NOx). Subjects were supine and orally water-loaded throughout the examination day. RESULTS: Irrespective of pretreatment, we observed an increase in FENa, heart rate, U-NOx, and a decrease in CH2O and brachial systolic BP during NaNO2 infusion. P-cGMP and U-cGMP did not change during infusion. We observed a consistent trend towards a reduction in central systolic BP, which was only significant after allopurinol. CONCLUSION: This study showed a robust BP lowering, natriuretic and anti-aquaretic effect of intravenous NaNO2 regardless of preceding enzyme inhibition. None of the three enzyme inhibitors used convincingly modified the pharmacological effects of NaNO2. The steady cGMP indicates little or no conversion of nitrite to NO. Thus the effect of NaNO2 may not be mediated by NO generation. TRIAL REGISTRATION: EU Clinical Trials Register, 2013-003404-39 . Registered December 3 2013.


Assuntos
Acetazolamida/farmacologia , Alopurinol/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Enalapril/farmacologia , Inibidores Enzimáticos/farmacologia , Rim/efeitos dos fármacos , Nitrito de Sódio/farmacologia , Vasodilatadores/farmacologia , Adulto , Pressão Sanguínea/fisiologia , Água Corporal/metabolismo , Artéria Braquial/fisiologia , Estudos Cross-Over , GMP Cíclico/metabolismo , Método Duplo-Cego , Feminino , Taxa de Filtração Glomerular , Humanos , Infusões Intravenosas , Rim/fisiologia , Masculino , Óxido Nítrico/metabolismo , Sistema Renina-Angiotensina/efeitos dos fármacos , Sódio/metabolismo , Nitrito de Sódio/administração & dosagem , Nitrito de Sódio/metabolismo , Vasodilatadores/administração & dosagem , Adulto Jovem
20.
Nitric Oxide ; 81: 1-10, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30217578

RESUMO

Cardiac transplantation has been limited by the inability to long preserve donor hearts safely. Hydrogen sulfide (H2S) has been recognized as an important gasotransmitter exerting potent cardioprotection from ischemia/reperfusion injury (I/R). Herein we investigated the cardioprotective effects of a novel long-term and slow-releasing H2S system, namely DATS-MSN, in heart preservation solution using a heart transplantation models. The release of H2S from DATS-MSN was slow and continuous in the University of Wisconsin solution (UW), correspondingly, DATS-MSN application demonstrated superior cardioprotective effects over the control and traditional H2S donors after 6 h heart preservation and 1 h reperfusion, associated with greater allograft performance including left ventricular developed pressure (LVDP) and dP/dt max, reduced plasmic CK-MB and troponin I levels, inhibited myocardial inflammation, increased antioxidant enzyme activities, preserved mitochondria structure and function, and decreased cardiomyocyte apoptosis index. Also, DATS-MSN application presented significant superiority in long-term allografts survival and function after 8 weeks of transplantation. In the in vitro experiments, cardiomyocytes injury from hypoxia was found to be relived with the treatment of DATS-MSN by anti-inflammatory effects via TLR4/NLRP3 pathway. The present work provides a long-term releasing H2S donor compatibly applied in the donor heart preservation, and preliminary explores its underlying mechanisms.


Assuntos
Cardiotônicos/farmacologia , Coração/fisiologia , Sulfeto de Hidrogênio/farmacologia , Preservação de Órgãos/métodos , Adenosina/farmacologia , Alopurinol/farmacologia , Compostos Alílicos/química , Animais , Apoptose , Glutationa/farmacologia , Coração/efeitos dos fármacos , Transplante de Coração , Sulfeto de Hidrogênio/química , Sulfeto de Hidrogênio/metabolismo , Insulina/farmacologia , Masculino , Morfolinas/química , Morfolinas/farmacologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocardite/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Soluções para Preservação de Órgãos/farmacologia , Compostos Organotiofosforados/química , Compostos Organotiofosforados/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Rafinose/farmacologia , Ratos Sprague-Dawley , Sulfetos/química , Doadores de Tecidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA