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1.
Ann Hematol ; 101(10): 2263-2270, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35997804

RESUMO

Failure of second-generation tyrosine kinase inhibitors (2GTKI) is a challenging situation in patients with chronic myeloid leukemia (CML). Asciminib, recently approved by the US Federal Drug Administration, has demonstrated in clinical trials a good efficacy and safety profile after failure of 2GTKI. However, no study has specifically addressed response rates to asciminib in ponatinib pretreated patients (PPT). Here, we present data on responses to asciminib from 52 patients in clinical practice, 20 of them (38%) with prior ponatinib exposure. We analyzed retrospectively responses and toxicities under asciminib and compared results between PPT and non-PPT patients.After a median follow-up of 30 months, 34 patients (65%) switched to asciminib due to intolerance and 18 (35%) due to resistance to prior TKIs. Forty-six patients (88%) had received at least 3 prior TKIs. Regarding responses, complete cytogenetic response was achieved or maintained in 74% and 53% for non-PPT and PPT patients, respectively. Deeper responses such as major molecular response and molecular response 4.5 were achieved in 65% and 19% in non-PPT versus 32% and 11% in PPT, respectively. Two patients (4%) harbored the T315I mutation, both PPT.In terms of toxicities, non-PPT displayed 22% grade 3-4 TEAE versus 20% in PPT. Four patients (20% of PPT) suffered from cross-intolerance with asciminib as they did under ponatinib.Our data supports asciminib as a promising alternative in resistant and intolerant non-PPT patients, as well as in intolerant PPT patients; the resistant PPT subset remains as a challenging group in need of further therapeutic options.


Assuntos
Antineoplásicos , Leucemia Mielogênica Crônica BCR-ABL Positiva , Piridazinas , Antineoplásicos/efeitos adversos , Resistencia a Medicamentos Antineoplásicos , Proteínas de Fusão bcr-abl/genética , Humanos , Imidazóis , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Niacinamida/análogos & derivados , Inibidores de Proteínas Quinases/efeitos adversos , Pirazóis , Piridazinas/efeitos adversos , Estudos Retrospectivos
2.
Arch Physiol Biochem ; 124(1): 54-60, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28844165

RESUMO

CONTEXT: Heat generation by brown adipose tissue (BAT) in response to temperature reduction seems to be entirely related to sympathetic nervous stimulation. OBJECTIVE: To analyse if temperature reduction and norepinephrine may differently affect the expression of proteins related to energy metabolism in BAT. MATERIALS AND METHODS: Isolated rats BAT was incubated with/without norepinephrine (10-6 mol/L, 24 h at 32 °C and 37 °C). RESULTS: In BAT, 32 °C increased the protein expression levels of carnitine palmitoyltransferase-I and -II, mitochondrial uncoupling protein-1 (UCP-1) and the expression and activity of lactate dehydrogenase. Mitochondrial F1-ATP synthase α-chain expression was decreased at 32 °C compared to 37 °C. Norepinephrine and at 32 °C exposure, UCP-1 expression was increased but cytochrome-c oxidase and F1-ATP synthase α-chain expression was reduced with respect to 37 °C. DISCUSSION: Sympathetic stimulation seems not to be the only factor associated with heat generation. CONCLUSIONS: Temperature reduction by itself exerts some different effects on the expression of proteins related to the energy metabolism than norepinephrine.


Assuntos
Tecido Adiposo Marrom/metabolismo , Metabolismo Energético , Mitocôndrias/metabolismo , Modelos Biológicos , Norepinefrina/metabolismo , Sistema Nervoso Simpático/metabolismo , Termogênese , Adenosina Trifosfatases/metabolismo , Tecido Adiposo Marrom/enzimologia , Tecido Adiposo Marrom/inervação , Animais , Western Blotting , Carnitina O-Palmitoiltransferase/metabolismo , Temperatura Baixa , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Técnicas In Vitro , Isoenzimas/metabolismo , L-Lactato Desidrogenase/metabolismo , Masculino , Mitocôndrias/enzimologia , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Fosforilação Oxidativa , Ratos Wistar , Proteína Desacopladora 1/metabolismo
3.
J Mol Endocrinol ; 54(2): 105-13, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25701828

RESUMO

It has been suggested that activated brown adipose tissue (BAT) shows increased glucose metabolic activity. However, less is known about metabolic activity of BAT under conditions of fasting and normal temperature. The aim of this study was to compare the possible differences in energetic metabolism between BAT and white adipose tissue (WAT) obtained from rabbits under the conditions of physiological temperature and 24 h after fasting conditions. The study was carried out on New Zealand rabbits (n=10) maintained for a period of 8 weeks at 23±2 °C. Food was removed 24 h before BAT and WAT were obtained. Protein expression levels of the glycolytic-related protein, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate dehydrogenase were higher in WAT than that in BAT. The expression level of carnitine palmitoyltransferase 1 (CPT1) and CPT2, two fatty acid mitochondrial transporters, and the fatty acid ß-oxidation-related enzyme, acyl CoA dehydrogenase, was higher in BAT than in WAT. Cytosolic malate dehydrogenase expression and malate dehydrogenase activity were higher in WAT than in BAT. However, lactate dehydrogenase expression and lactate content were significantly higher in BAT than in WAT. In summary, this study for the first time, to our knowledge, has described how under fasting and normal temperature conditions rabbit BAT seems to use anaerobic metabolism to provide energetic fuel, as opposed to WAT, where the malate-aspartate shuttle and, therefore, the gluconeogenic pathway seem to be potentiated.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Jejum , Temperatura , Aconitato Hidratase/metabolismo , Tecido Adiposo Marrom/enzimologia , Tecido Adiposo Branco/enzimologia , Animais , Western Blotting , Ácidos Graxos/metabolismo , Glucose/metabolismo , Glicólise , L-Lactato Desidrogenase/metabolismo , Ácido Láctico/metabolismo , Metabolismo dos Lipídeos , Malato Desidrogenase/metabolismo , Proteínas Mitocondriais/metabolismo , Coelhos
4.
Biomed Res Int ; 2014: 257517, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24790994

RESUMO

The aim of this study was to investigate the frequency and mutation status of the immunoglobulin heavy variable chain (IGHV) in a cohort of 224 patients from northwest and central region of Spain diagnosed with chronic lymphocytic leukemia (CLL), and to correlate it with cytogenetic abnormalities, overall survival (OS) and time to first treatment (TTFT). 125 patients had mutated IGHV, while 99 had unmutated IGHV. The most frequently used IGHV family was IGHV3, followed by IGHV1 and IGHV4. The regions IGHV3-30, IGHV1-69, IGHV3-23, and IGHV4-34 were the most commonly used. Only 3.1% of the patients belonged to the subfamily IGHV3-21 and we failed to demonstrate a worse clinical outcome in this subgroup. The IGHV4 family appeared more frequently with mutated pattern, similar to IGHV3-23 and IGHV3-74. By contrast, IGHV1-69 was expressed at a higher frequency in unmutated CLL patients. All the cases from IGHV3-11 and almost all from IGHV5-51 subfamily belonged to the group of unmutated CLL.


Assuntos
Rearranjo Gênico/genética , Genes de Cadeia Pesada de Imunoglobulina/genética , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Leucemia Linfocítica Crônica de Células B/epidemiologia , Leucemia Linfocítica Crônica de Células B/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Feminino , Marcadores Genéticos/genética , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação/genética , Prevalência , Fatores de Risco , Espanha/epidemiologia , Análise Espaço-Temporal
5.
Water Res ; 54: 170-8, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24568786

RESUMO

The disinfection performance of a unique process of adsorption combined with electrochemical treatment is evaluated. A flake graphite intercalation compound adsorbent was used, which is effective for the removal of organic contaminants and is amenable to anodic electrochemical regeneration. Adsorption of Escherichia coli on the graphite flake was followed by electrochemical treatment under a range of experimental conditions in a sequential batch reactor. The adsorption of E. coli cells was found to be a fast process and was capable of removing >99.98% of cells from solution after 5 min with a ca. 6.5-log10 reduction in E. coli concentration after 10 min. With electrochemical treatment the adsorbent could be reused, with no decrease in E. coli adsorption observed over five cycles. In the presence of chloride, >8.5-log10 reduction of E. coli concentration was achieved. Disinfection was found to be less effective in the absence of chloride. However, selection of appropriate operating conditions enabled effective disinfection in a chloride free system, reducing the potential for formation of disinfection by-products. The energy consumption required to achieve >8.5-log10 disinfection was 2-7 kWh m(-3).


Assuntos
Desinfecção/métodos , Técnicas Eletroquímicas/métodos , Microbiologia da Água , Água , Adsorção , Técnicas de Cultura Celular por Lotes , Cloro/análise , Eletricidade , Escherichia coli/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Fatores de Tempo
6.
Leukemia ; 28(1): 166-73, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23604227

RESUMO

Although multiparameter flow cytometry (MFC) has demonstrated clinical relevance in monoclonal gammopathy of undetermined significance (MGUS)/myeloma, immunophenotypic studies on the full spectrum of Waldenström's Macroglobulinemia (WM) remain scanty. Herein, a comprehensive MFC analysis on bone marrow samples from 244 newly diagnosed patients with an immunoglobulin M (IgM) monoclonal protein was performed, including 67 IgM-MGUS, 77 smoldering and 100 symptomatic WM. Our results show a progressive increase on the number and light-chain-isotype-positive B-cells from IgM-MGUS to smoldering and symptomatic WM (P<.001), with only 1% of IgM-MGUS patients showing >10% B cells or 100% light-chain-isotype-positive B-cells (P<.001). Complete light-chain restriction of the B-cell compartment was an independent prognostic factor for time-to progression in smoldering WM (median 26 months; HR: 19.8, P=0.001) and overall survival in symptomatic WM (median 44 months; HR: 2.6, P=0.004). The progressive accumulation of light-chain-isotype-positive B-cells accompanied the emergence of a characteristic Waldenstrom's phenotype (CD22(+dim) / CD25+ /CD27+ / IgM+) that differed from other B-NHL by negative expression of CD5, CD10, CD11c or CD103. In contrast to myeloma, light-chain-isotype-positive plasma cells in IgM monoclonal gammopathies show otherwise normal antigenic expression. Our results highlight the potential value of MFC immunophenotyping for the characterization of the Waldenström's clone, as well as for the differential diagnosis, risk of progression and survival in WM.


Assuntos
Citometria de Fluxo/métodos , Imunoglobulina M/sangue , Gamopatia Monoclonal de Significância Indeterminada/sangue , Macroglobulinemia de Waldenstrom/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco
7.
Nutr Metab Cardiovasc Dis ; 23(11): 1107-14, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23434394

RESUMO

BACKGROUND AND AIM: To investigate whether rosuvastatin can improve insulin sensitivity in overweight rats having a high fat diet (HFD). The potential mechanisms involved in this action were evaluated, including SIRT-1, other factors involved in glucose metabolism and stress signaling pathways. METHODS AND RESULTS: Male Wistar rats (n = 30) were divided into three groups: (i) rats fed a standard diet (3.5% fat); (ii) rats fed a HFD (33.5% fat); and (iii) rats fed a HFD and treated with rosuvastatin (15 mg/kg/day). Evolution: 7 weeks. HFD rats showed increased body, epididymal and lumbar adipose tissue weights. Plasma levels of cholesterol, triglycerides, VLDL, glucose and insulin and leptin/adiponectin ratio were higher in HFD rats, and rosuvastatin treatment reduced them. SIRT-1, p53, PGC-1α, PPAR-γ and GLUT-4 protein levels in white adipose tissue (WAT) were lower, and JNK was higher in HFD rats compared to controls. Rosuvastatin treatment normalized expression of these mediators. Endothelium-dependent relaxation was reduced in mesenteric rings from HFD rats compared to controls and rosuvastatin enhanced it in HFD rats. CONCLUSION: Rosuvastatin treatment reduced insulin resistance without affecting body weight or WAT loss in HFD rats. Reduction of leptin and JNK, and enhancement of SIRT-1, p53, PGC-1α, PPAR-γ and GLUT-4 expression in WAT could contribute to insulin sensitization. Normalization of SIRT-1 expression in WAT could be considered a key novel mechanism that aids in explaining the beneficial effects of rosuvastatin on the amelioration of glucose metabolism and the arrangement of multiple signaling pathways participating in insulin resistance in overweight HFD rats.


Assuntos
Tecido Adiposo Branco/efeitos dos fármacos , Fluorbenzenos/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperlipidemias/prevenção & controle , Resistência à Insulina , Sobrepeso/fisiopatologia , Pirimidinas/uso terapêutico , Sirtuína 1/metabolismo , Sulfonamidas/uso terapêutico , Adipocinas/sangue , Adipocinas/metabolismo , Tecido Adiposo Branco/imunologia , Tecido Adiposo Branco/metabolismo , Animais , Dieta Hiperlipídica/efeitos adversos , Regulação para Baixo/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Transportador de Glucose Tipo 4/metabolismo , Hiperlipidemias/etiologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Sobrepeso/etiologia , Sobrepeso/imunologia , Sobrepeso/metabolismo , PPAR gama/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Ratos , Ratos Wistar , Rosuvastatina Cálcica , Fatores de Transcrição/metabolismo , Vasodilatação/efeitos dos fármacos
8.
Exp Physiol ; 98(5): 999-1008, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23335007

RESUMO

Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is emerging as a novel factor that plays a critical role in integrating signalling pathways in the control of cellular and systemic metabolism. We investigated the role of vascular expression of PGC-1α and related factors, such as sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor γ (PPARγ) and adiponectin, during the atherosclerotic process. Endothelial function, vascular superoxide anion production and inflammatory mediators were also evaluated. This study was carried out in male New Zealand rabbits fed a diet containing 0.5% cholesterol and 14% coconut oil for 8 weeks. Animals developed mixed dyslipidaemia and atherosclerotic lesions, which were associated with endothelial dysfunction, aortic overproduction of superoxide anions and inflammation. Expression of PGC-1α, SIRT1, PPARγ and adiponectin was reduced (P<0.05) in aorta from atherosclerotic rabbits. Levels of PGC-1α were correlated negatively (P<0.05) with total cholesterol levels, aortic superoxide anion production and tumour necrosis factor-α expression, and positively (P<0.05) with maximal relaxation in response to acetylcholine. The observed results suggest that PGC-1α could be considered to be a link between the main atherosclerotic processes (endothelial dysfunction, oxidation and inflammation) and alterations of other factors involved in vascular wall integrity, such as SIRT1, PPARγ and adiponectin.


Assuntos
Aterosclerose/fisiopatologia , Fatores de Transcrição/metabolismo , Adiponectina/biossíntese , Animais , Aorta/metabolismo , Aterosclerose/induzido quimicamente , Aterosclerose/patologia , Antígenos CD36/biossíntese , Colesterol na Dieta , Óleo de Coco , Endotélio Vascular/efeitos dos fármacos , Lipídeos/sangue , Masculino , PPAR gama/biossíntese , Óleos de Plantas , Coelhos , Sirtuína 1/biossíntese , Molécula 1 de Adesão de Célula Vascular/biossíntese , Vasodilatação
9.
J Physiol Pharmacol ; 62(1): 87-94, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21451213

RESUMO

UNLABELLED: Several factors, including mineralocorticoids, have been implicated in the renal damage associated with hypertension. Peroxisome proliferator activated receptor gamma (PPAR-γ) agonists improve renal damage associated with different pathologies. Therefore, our hypothesis was that mineralocorticoid receptor blockade ameliorates renal damage associated with hypertension and that this improvement may be mediated by PPAR-γ. Spontaneously hypertensive rats (SHR) were treated with either vehicle or eplerenone, a mineralocorticoid receptor antagonist, at two different doses: 30 and 100 mg/kg/day for 10 weeks. Age-matched Wistar Kyoto rats (WKY) were used as a normotensive reference group. SHR showed tubulointersticial fibrosis and mild tubular atrophy. These alterations were accompanied by increases in renal cortex gene expression of transforming growth factor beta (TGF-ß) connective tissue growth factor (CTGF) and phosphorylated Smad2 protein levels, factors involved in the fibrotic response. Interleukin 1-beta (IL-1ß) and tumor necrosis factor alpha (TNF-α) gene expression were also increased. By contrast, lysyl oxidase (LOX) expression and PPAR-γ protein levels were decreased in SHR as compared with normotensive animals. Only the high dose of eplerenone was able to reduce blood pressure and partially prevent LOX down-regulation in SHR. Both eplerenone doses significantly ameliorated interstitial fibrosis and tubular atrophy, reduced TGF-ß, CTGF and cytokine gene expression, and decreased Smad2 activation, while normalizing PPAR-γ protein levels. CONCLUSIONS: Mineralocorticoid receptor activation participates in hypertension-associated renal damage. This effect seems to involve stimulation of both fibrotic and inflammatory processes mediated (at least in part) by a down-regulation of PPAR-γ that can favour an up-regulation of the TGF-ß/Smad signalling pathway.


Assuntos
Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Nefropatias/tratamento farmacológico , Nefropatias/metabolismo , PPAR gama/metabolismo , Espironolactona/análogos & derivados , Animais , Pressão Sanguínea/efeitos dos fármacos , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Citocinas/genética , Regulação para Baixo , Eplerenona , Expressão Gênica , Hipertensão/genética , Hipertensão/fisiopatologia , Córtex Renal/metabolismo , Córtex Renal/fisiopatologia , Nefropatias/genética , Nefropatias/fisiopatologia , Masculino , Antagonistas de Receptores de Mineralocorticoides , PPAR gama/agonistas , PPAR gama/genética , Proteína-Lisina 6-Oxidase/genética , Proteína-Lisina 6-Oxidase/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Receptores de Mineralocorticoides/metabolismo , Transdução de Sinais , Proteína Smad2/metabolismo , Espironolactona/farmacologia , Regulação para Cima
10.
Leukemia ; 25(4): 697-706, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21252988

RESUMO

Disappearance of normal bone marrow (BM) plasma cells (PC) predicts malignant transformation of monoclonal gammopathy of undetermined significance (MGUS) and smoldering myeloma (SMM) into symptomatic multiple myeloma (MM). The homing, behavior and survival of normal PC, but also CD34(+) hematopoietic stem cells (HSC), B-cell precursors, and clonal PC largely depends on their interaction with stromal cell-derived factor-1 (SDF-1) expressing, potentially overlapping BM stromal cell niches. Here, we investigate the distribution, phenotypic characteristics and competitive migration capacity of these cell populations in patients with MGUS, SMM and MM vs healthy adults (HA) aged >60 years. Our results show that BM and peripheral blood (PB) clonal PC progressively increase from MGUS to MM, the latter showing a slightly more immature immunophenotype. Of note, such increased number of clonal PC is associated with progressive depletion of normal PC, B-cell precursors and CD34(+) HSC in the BM, also with a parallel increase in PB. In an ex vivo model, normal PC, B-cell precursors and CD34(+) HSC from MGUS and SMM, but not MM patients, were able to abrogate the migration of clonal PC into serial concentrations of SDF-1. Overall, our results show that progressive competition and replacement of normal BM cells by clonal PC is associated with more advanced disease in patients with MGUS, SMM and MM.


Assuntos
Células da Medula Óssea/citologia , Células-Tronco Hematopoéticas/citologia , Mieloma Múltiplo/patologia , Paraproteinemias/patologia , Plasmócitos/citologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos B/citologia , Linfócitos B/metabolismo , Células da Medula Óssea/metabolismo , Estudos de Casos e Controles , Movimento Celular , Células Cultivadas , Células Clonais , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Células-Tronco Hematopoéticas/metabolismo , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/metabolismo , Paraproteinemias/metabolismo , Plasmócitos/metabolismo , Estudos Prospectivos
11.
Int J Cancer ; 112(5): 884-9, 2004 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-15386370

RESUMO

Although multiple myeloma (MM) is predominantly a disease of the elderly, few studies have focused on the identification of prognostic factors in this group of patients. Four hundred twenty five MM patients >65 years were uniformly treated with chemotherapy (MP or VCMP/VBAD). Multivariate analysis identified 4 factors with independent unfavorable prognostic influence: high percentage of S-phase bone marrow plasma cells (>2.5%); elevated beta(2) microglobulin (B2M) (>4 mg/L); age >80 years old; and LDH serum levels (above normal limit). The S-phase value was the most powerful independent prognostic factor to discriminate subgroups of patients with different prognosis. Thus, 3 main risk categories could be identified according to S-phase values: 3%, with median survivals of 34, 22 and 12 months, respectively (p < 0.0001). Our study also proved the value for elderly patients of the recently developed International Score System (ISS) based on B2M and albumin. Furthermore, the number of S-phase cells helped to subdivide the ISS III Group identifying a subset of patients with very poor prognosis defined by an additional high S-phase, who displayed a median survival of only 8 months. These results demonstrate that elderly patients can be accurately classified according to prognosis, which may be particularly valuable when comparing the efficacy of new treatment strategies. Moreover, our results underline the high prognostic value of proliferative activity of PC, a parameter that should be considered in routine laboratory investigations of MM.


Assuntos
Biomarcadores Tumorais/análise , Proliferação de Células , Mieloma Múltiplo/classificação , Mieloma Múltiplo/patologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Ciclo Celular , Feminino , Humanos , Masculino , Prognóstico , Estudos Prospectivos , Fatores de Risco , Análise de Sobrevida
13.
J Hypertens ; 19(3 Pt 2): 539-45, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11327627

RESUMO

OBJECTIVES: To evaluate the relative participation of nitric oxide (NO), endothelium-derived hyperpolarizing factor (EDHF) and prostanoids in the relaxing responses induced by acetylcholine and isoproterenol in isolated coronary arteries from adult Wistar- Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). DESIGN AND METHODS: Male adult WKY rats and SHR were used in the study. Segments from left coronary arteries (approximately 350-380 microm internal diameter and 2 mm long) were mounted in an isometric myograph and pre-contracted with serotonin. Dose-response curves to acetylcholine and isoproterenol were carried out in absence and presence of the NO synthesis inhibitor NG-nitro-L-arginine methyl ester (LNAME), the inhibitor of the cyclo-oxygenase, indomethacin and KCI. Areas under the respective dose-response curves were used to calculate the approximate relative participation of NO, EDHF and prostanoids. RESULTS: Relaxations to either acetylcholine or isoproterenol were lower in SHR than in WKY rats. In WKY rats, presence of LNAME diminished (P< 0.05) relaxation to acetylcholine from 10(-9) to 10(-6) mol/l, and induced a contracting response at 10(-5) and 10(-4) mol/l of acetylcholine. Addition of indomethacin did not significantly affect dose-related relaxation to acetylcholine 10(-9) to 10(-6) mol/l in WKY rats, and reduced (P < 0.05) the contracting response observed at 10(-5) mol/l of acetylcholine. In SHR, addition of LNAME markedly reduced (P< 0.05) acetylcholine relaxations, but did not produce any contracting effect. Addition of indomethacin on top of LNAME slightly (P< 0.05) enhanced relaxing response to acetylcholine in SHR. Presence of LNAME in the media diminished (P < 0.05) relaxation to isoproterenol in both WKY rats and SHR. Addition of indomethacin on top of LNAME increased (P< 0.05) isoproterenol-relaxing response to levels similar to and higher than control conditions in WKY rats and SHR, respectively. Addition of KCI blunted both acetylcholine- and isoproterenol-relaxations in both groups. CONCLUSIONS: NO and EDHF are the main endothelium-derived relaxing factors underlying acetylcholine and isoproterenol relaxations in rat coronary arteries, respectively. EDHF reduction, and not only NO reduction play a key role in the diminished coronary relaxations induced by acetylcholine and isoproterenol in SHR. An arachidonic acid derivative with contracting activity released by acetylcholine and isoproterenol in a differential manner, could oppose the relaxing actions of NO and EDHF.


Assuntos
Fatores Biológicos/fisiologia , Vasos Coronários/fisiopatologia , Hipertensão/fisiopatologia , Vasodilatação , Acetilcolina/farmacologia , Animais , Vasos Coronários/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Isoproterenol/farmacologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Vasoconstrição , Vasodilatadores/farmacologia
14.
Nephrol Dial Transplant ; 16 Suppl 1: 40-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11369819

RESUMO

BACKGROUND: Numerous studies have shown that elevated plasma cholesterol can exacerbate renal disease. However, the effect of lipids on renal structure and vascular function in normal kidneys is less well established. Therefore, the aim of this study was to evaluate the impact of hypercholesterolaemia on glomerular structure and vascular reactivity of segmental arteries in rabbits. In addition, we also studied whether or not atorvastatin can prevent these structural and vascular alterations in hypercholesterolaemic rabbits. METHODS: Male New Zealand rabbits were fed either a normal rabbit chow or a diet containing 1% cholesterol and treated or not with atorvastatin (1 mg/kg/day) for 12 weeks. Dose-response curves to acetylcholine (10(-9)-10(-4) mol/l) and sodium nitroprusside (10(-9)-10(-4) mol/l) were studied in segmental arteries in the presence or absence of the thromboxane A2/PGH2 receptor antagonist ifetroban (10(-5) mol/l). Glomerular size and structure were also evaluated. RESULTS: Compared with control animals, hypercholesterolaemic rabbits presented glomerular hypertrophy and several types of injuries (capillary collapse, hyalinosis and alterations of Bowman's capsule), suggesting diffuse glomerulosclerosis. Segmental arteries also showed relaxing responses to acetylcholine and sodium nitroprusside which were lower than and similar to, respectively, those of control animals. The presence of ifetroban improved the acetylcholine response only in hypercholesterolaemic rabbits. Atorvastatin treatment prevented vascular and most glomerular changes associated with hypercholesterolaemia even in the presence of very high cholesterol levels. CONCLUSIONS: Atorvastatin exerts a protective effect on renal damage associated with hypercholesterolaemia even in the presence of deleterious levels of plasma cholesterol.


Assuntos
Anticolesterolemiantes/uso terapêutico , Endotélio Vascular/efeitos dos fármacos , Glomerulosclerose Segmentar e Focal/prevenção & controle , Ácidos Heptanoicos/uso terapêutico , Hipercolesterolemia/complicações , Hipercolesterolemia/tratamento farmacológico , Pirróis/uso terapêutico , Circulação Renal/efeitos dos fármacos , Acetilcolina/farmacologia , Animais , Atorvastatina , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Colesterol na Dieta , Modelos Animais de Doenças , Endotélio Vascular/fisiologia , Endotélio Vascular/fisiopatologia , Rim/efeitos dos fármacos , Rim/patologia , Masculino , Nitroprussiato/farmacologia , Oxazóis/farmacologia , Fenilefrina/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Coelhos , Circulação Renal/fisiologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia
15.
Hypertension ; 34(4 Pt 2): 969-75, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10523393

RESUMO

The effects of angiotensin (AT)(1) receptor antagonists on functional and morphological alterations associated with atherosclerosis are not well known. The current study was performed to examine the long-term effects of valsartan (3 or 10 mg/kg per day for 10 weeks) on endothelial function and structural changes in aorta from rabbits fed with either a control diet or a cholesterol-enriched diet. Rabbits fed with the cholesterol-rich diet showed higher (P<0.05) plasma levels of cholesterol than did controls. Treatment with valsartan (3 or 10 mg/kg per day) did not alter plasma cholesterol levels or systolic arterial pressure in any group. Contractions induced by angiotensin II were comparable in both control and hypercholesterolemic rabbits and were markedly reduced by treatment with valsartan. Relaxations induced by acetylcholine were lower in hypercholesterolemic rabbits than in controls. Treatment with valsartan (3 or 10 mg/kg per day) enhanced (P<0.05) this response in hypercholesterolemic rabbits but not in controls. Lumen and media cross-sectional areas were comparable in control and hypercholesterolemic rabbits. Vessel area was higher (P<0.05) in hypercholesterolemic rabbits than in controls. Intimal lesion was 29.5+/-6% in cholesterol-fed rabbits and nonexistent in control rabbits. Treatments with 3 and 10 mg/kg per day valsartan reduced (P<0.05) intimal lesion to 2.4+/-0.7% and 2.7+/-0.9%, respectively, and increased lumen area in hypercholesterolemic rabbits. No changes in either vessel or media cross-sectional areas were observed in these animals. In summary, angiotensin II, through AT(1) receptors, appears to play a key role in the development of the vascular functional and structural changes associated with hypercholesterolemia. AT(1) receptor antagonists, besides their antihypertensive effects, could be an important therapeutic tool to reduce the development of atherosclerosis.


Assuntos
Antagonistas de Receptores de Angiotensina , Anti-Hipertensivos/farmacologia , Arteriosclerose/tratamento farmacológico , Endotélio Vascular/fisiopatologia , Tetrazóis/farmacologia , Valina/análogos & derivados , Angiotensina I/fisiologia , Animais , Anti-Hipertensivos/uso terapêutico , Aorta/patologia , Aorta/fisiopatologia , Arteriosclerose/patologia , Arteriosclerose/fisiopatologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Masculino , Coelhos , Receptores de Angiotensina/fisiologia , Tetrazóis/uso terapêutico , Túnica Íntima/patologia , Túnica Íntima/fisiopatologia , Valina/farmacologia , Valina/uso terapêutico , Valsartana
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