RESUMO
INTRODUCTION: Growing evidence shows a high correlation between extensive use of central nervous system-acting drugs (CNSADs) in elderly patients and adverse drug reactions (ADRs) such as falls, fractures, and mortality. RESEARCH QUESTION: Are results of cognitive testing with the Mini Mental Status Examination (MMSE) influenced by use of CNSADs? SETTING: Geriatric inpatient service for acute, subacute, and rehabilitation care. METHODS: Secondary combined analysis of two prospective, single-center study cohorts (PROPSYC, 2011 and AGE OUT, 2012) with identical procedure for the MMSE at a tertiary hospital. RESULTS: Overall, 395 patients were included, 144 male (M) and 251 female (F). Mean age was 80.0 ± 8.4 years (M 76.7 ± 9.1, F 81.9 ± 7.3, p = 0.0000). Mean MMSE points were 22.9 ± 4.8 (M 23.2 ± 4.6, F 22.6 ± 5.0, p = 0.211). In total, 258 patients (65.3 %) used drugs with potential adverse cognitive properties. Analgesics with central activity were given to 117 of 395 patients (29.6 %). Low-potency opioids (tramadol hydrochloride, tilidine) were identified in 60 patients and high-potency opioids in 57 patients. Antidepressants were used in 66 patients, benzodiazepines in 26, and hypnotics in 11, while 38 patients received other CNSADs. We only found significant correlations with the results of cognitive testing for sedatives (diazepam and oxazepam, Pearson's r - 0.79, p = 0.05), but not for lorazepam. CONCLUSION: Our analysis shows an influence of sedatives (diazepam and oxazepam, but not lorazepam) on cognitive testing with the MMSE in users of CNSADs.
Assuntos
Fármacos do Sistema Nervoso Central/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Hospitalização , Entrevista Psiquiátrica Padronizada , Idoso , Idoso de 80 Anos ou mais , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/uso terapêutico , Antidepressivos/efeitos adversos , Antidepressivos/uso terapêutico , Benzodiazepinas/efeitos adversos , Benzodiazepinas/uso terapêutico , Fármacos do Sistema Nervoso Central/uso terapêutico , Transtornos Cognitivos/diagnóstico , Diazepam/efeitos adversos , Diazepam/uso terapêutico , Feminino , Humanos , Hipnóticos e Sedativos/efeitos adversos , Hipnóticos e Sedativos/uso terapêutico , Lorazepam/efeitos adversos , Lorazepam/uso terapêutico , Masculino , Oxazepam/efeitos adversos , Oxazepam/uso terapêuticoRESUMO
BACKGROUND: Glycated proteins (advanced glycation endproducts, AGE) in tissue are associated with degenerative diseases. This study evaluated the role of sRAGE (soluble receptor for advanced glycation endproducts), a decoy receptor of AGEs in blood, for the outcome of patients after coronary artery bypass grafting (CABG). METHODS: A total of 90 patients undergoing CABG were analysed in two centres. Perioperative blood samples were collected before surgery up to 1 week postoperatively. sRAGE was measured by ELISA. Patients were subdivided regarding age (< 64 versus > 70 years, 14 % versus 35 % female), euroSCORE (< 3 versus > 4, 14 % versus 29 % female) and sRAGE changes between sternotomy and end of the operation (< 30 % versus > 45 %, 33 % versus 33 % female) and subsequently analysed with respect of postoperative outcome parameters. RESULTS: Preoperative sRAGE values did not correlate with the outcome of the patients. sRAGE levels increase within 10 min from 1,539 ± 96 to 5,311 ± 187 pg/ml after sternotomy, then returning to baseline levels within 2 days after surgery. Comparing the analysed possible risk factors age, euroSCORE and sRAGE changes, no difference was observed regarding 30-day mortality. Age and the euroSCORE are superior with respect of tachyarrythmia, whereas sRAGE kinetics seems to be superior with respect of prolonged postoperative respiration time/stay in the intensive care unit or catecholamine support. CONCLUSION: A prolonged, increased intraoperative sRAGE level is a new outcome predictor for patients undergoing CABG surgery, mutually complementary to the euroSCORE.
Assuntos
Ponte de Artéria Coronária/mortalidade , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/cirurgia , Avaliação de Resultados em Cuidados de Saúde/métodos , Receptores Imunológicos/sangue , Distribuição por Idade , Idoso , Biomarcadores/sangue , Doença da Artéria Coronariana/sangue , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Monitorização Intraoperatória/estatística & dados numéricos , Prevalência , Prognóstico , Receptor para Produtos Finais de Glicação Avançada , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Distribuição por Sexo , Taxa de Sobrevida , Resultado do TratamentoRESUMO
To investigate the effects of the commonly-used immunomodulators l-glutamine, l-alanine, and the combination of both l-alanyl-l-glutamine (Dipeptamin(®)) on intracellular expression of IL-6, IL-8, and TNF-α during endotoxemia, lipopolysaccharide (LPS)-stimulated human monocytes in a whole blood system were investigated by flow cytometry. Whole blood of twenty-seven healthy volunteers was stimulated with LPS and incubated with three different amino acid solutions (1. l-glutamine, 2. l-alanine, 3. l-alanyl-l-glutamine, each concentration 2 mM, 5 mM, incubation time 3 h). CD14(+) monocytes were phenotyped in whole-blood and intracellular expression of cytokines was assessed by flow cytometry. Our investigations showed for the first time in whole blood probes, imitating best physiologically present cellular interactions, that l-glutamine caused a dose-independent inhibitory effect on IL-6 and TNF-α production in human monocytes stimulated with LPS. However, l-alanine had contrary effects on IL-6 expression, significantly upregulating expression of IL-6 in LPS-treated monocytes. The impact of l-alanine on the expression of TNF-α was comparable with glutamine. Neither amino acid was able to affect IL-8 production in LPS-stimulated monocytes. The combination of both did not influence significantly IL-6 and IL-8 expression in monocytes during endotoxemia, however strongly reduced TNF-α production. For the regulation of TNF-α, l-glutamine, l-alanine and the combination of both show a congruent and exponentiated downregulating effect during endotoxemia, for the modulation of IL-6, l-glutamine and l-alanine featured opposite regulation leading to a canceling impact of each other when recombining both amino acids.
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Alanina/farmacologia , Glutamina/farmacologia , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Lipopolissacarídeos/farmacologia , Monócitos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Dipeptídeos/farmacologia , Endotoxemia/sangue , Citometria de Fluxo , Humanos , Interleucina-6/sangue , Interleucina-8/sangue , Espaço Intracelular/metabolismo , Monócitos/efeitos dos fármacos , Fator de Necrose Tumoral alfa/sangueRESUMO
OBJECTIVE: This randomized prospective study was initiated to clarify whether individualized heparin and protamine dosing has immediate effects on hemostatic activation and platelet function in adult cardiac surgery. METHODS: Sixty adults undergoing elective coronary artery bypass grafting (CABG) were assigned to receive individualized heparin and protamine (HMS group, n= 29) or a standard dose (ACT group, n=24). Measures of thrombin generation and Multiplate (Verum Diagnostica, Munich, Germany) platelet function tests were performed before and after cardiopulmonary bypass (CPB). RESULTS: HMS patients received higher heparin (p = 0.006) and lower protamine (p<0.001) doses. Post-CPB, HMS managed patients showed significantly lower thrombin generation (thrombin-antithrombin (TAT) p<0.02) than the ACT group. Moreover, HMS managed patients had a better preservation of platelet function (COL p = 0.013; ADP p = 0.04; TRAP p = 0.04). CONCLUSION: An individualized and stable heparin concentration and appropriate dosing of protamine can reduce thrombin generation and preserve platelet function, even in short-time CPB.
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Antifibrinolíticos/uso terapêutico , Ponte de Artéria Coronária , Fibrinolíticos/uso terapêutico , Antagonistas de Heparina/uso terapêutico , Heparina/uso terapêutico , Protaminas/uso terapêutico , Ácido Tranexâmico/uso terapêutico , Adulto , Idoso , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Ponte de Artéria Coronária/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ativação Plaquetária/efeitos dos fármacos , Estudos ProspectivosRESUMO
The incidence of diabetes has increased in the recent years. Diabetes is characterized by increased sugar concentrations in the blood. Due to this dysregulation, more carbohydrate-induced modification of proteins - so-called advanced glycation end products (AGEs) - are formed endogenously by non-enzymatic reactions. These are discussed to be at least in part responsible for diabetes-associated diseases. The accumulation of AGEs in the tissue can be used as a biomarker for patient outcome. In contrast, the effects of the uptake of AGEs from nutrition are still unclear.
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Glicemia/metabolismo , Proteínas Sanguíneas/metabolismo , Diabetes Mellitus/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Modelos Biológicos , Animais , HumanosRESUMO
BACKGROUND: The metabolic syndrome is defined by the presence of obesity, insulin resistance, dyslipidemia, and hypertension. Advanced glycation end products (AGEs) are stable end products of the Maillard reaction, whereby AGE accumulation is considered not only a biomarker of aging but is also associated with several degenerative diseases. AGEs are recognized by several receptor molecules of which the receptor of AGEs (RAGE) is currently the most intensively studied receptor. Activation of RAGE causes an unfavorable proinflammatory state and deletion of RAGE in diabetic animals has been reported to protect against atherosclerosis. AGEs and a high fat diet are associated with cardiovascular diseases, whereas is still not clear whether a direct link between high fat nutrition and AGEs exists in vivo. MATERIALS AND METHODS: C57BL/6 and C57BL/6 RAGE -/- mice were fed a high fat diet to induce obesity. Weight, insulin, lipid levels, AGE modifications, and cardiac gene expression were analyzed. RESULTS: The absence of RAGE resulted in accelerated weight gain, increased plasma cholesterol, and higher insulin levels in obese mice. The hearts of normal and obese RAGE -/- mice contained lower levels of the AGE arginine-pyrimidine and 3DG-imidazolone than RAGE + / + animals. RAGE -/- mice also exhibited lower expression of the genes encoding the antioxidative enzymes MnSOD, Cu/ZnSOD, and ceruloplasmin in cardiac tissue, whereas the AGE receptors AGER-1, -2, and -3 were equally expressed in both genotypes. Obese mice of both strains expressed increased amounts of AGER-2. Only obese RAGE + / + mice exhibited a reduced mRNA accumulation of Cu/Zn SOD. CONCLUSION: These data suggest that RAGE is involved in the development of obesity and insulin resistance.
Assuntos
Dieta Hiperlipídica/métodos , Gorduras na Dieta/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Obesidade/fisiopatologia , Espécies Reativas de Oxigênio/metabolismo , Receptores Imunológicos/metabolismo , Aumento de Peso , Animais , Camundongos , Camundongos Knockout , Receptor para Produtos Finais de Glicação AvançadaRESUMO
The slow procession of the primary mechanisms of aging leads, at first, to unnoticed changes in the vascular system. Endothelial dysfunction is one of the earliest markers in aging vessels, caused by oxidative stress via the reduction of the availability of NO, on the one hand, and the nitrosylation of proteins, on the other hand. At the same time, glycation of the proteins of the extracellular matrix leads to stiffening of the vessel wall. Together with the loss of elastic fibers, e.g., elastin, this leads to the age-related changes of the vessels. Knowledge of these primary mechanisms of aging may lead to the development of new drugs.
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Envelhecimento , Vasos Sanguíneos/fisiopatologia , Endotélio Vascular/fisiopatologia , Produtos Finais de Glicação Avançada/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Glicosilação , Humanos , Modelos CardiovascularesRESUMO
The demand and requirements for valid, practicable, and reliable procedures for age diagnosis are increasing worldwide. In contrast, few studies and only a small number of procedures exist. The authors review the theoretical and methodological requirements for the development of models for age diagnostics. They describe the fundamentals for further studies, based on an analysis of current gerontological research in this area. A following publication will report the valid systems measuring vitality and biofunctional age(ing) of human beings.
Assuntos
Doença Crônica/classificação , Sistemas de Apoio a Decisões Clínicas , Diagnóstico por Computador/métodos , Avaliação Geriátrica/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , MasculinoRESUMO
Self-rated health (SRH) is one of the most frequently used indicators in health and social research. Its robust association with mortality in very different populations implies that it is a comprehensive measure of health status and may even reflect the condition of the human organism beyond clinical diagnoses. Yet the biological basis of SRH is poorly understood. We used data from three independent European population samples (N approx. 15,000) to investigate the associations of SRH with 150 biomolecules in blood or urine (biomarkers). Altogether 57 biomarkers representing different organ systems were associated with SRH. In almost half of the cases the association was independent of disease and physical functioning. Biomarkers weakened but did not remove the association between SRH and mortality. We propose three potential pathways through which biomarkers may be incorporated into an individual's subjective health assessment, including (1) their role in clinical diseases; (2) their association with health-related lifestyles; and (3) their potential to stimulate physical sensations through interoceptive mechanisms. Our findings indicate that SRH has a solid biological basis and it is a valid but non-specific indicator of the biological condition of the human organism.
Assuntos
Biomarcadores , Autoavaliação Diagnóstica , Nível de Saúde , Autorrelato , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Biomarcadores/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
OBJECTIVE: Although home blood glucose (HBG) profiles correlate closely with HbA1c, the strength of the relationship during pregnancy is unclear due to physiological changes which can induce subnormal HbA1c levels. We therefore aimed to establish the strength of the association between mean HBG profiles and HbA1c in diabetic pregnancies and whether HbA1c levels and glycaemic variability affects neonatal birth weight (NBW). STUDY DESIGN: 7-point glycaemic profiles performed throughout pregnancy were obtained retrospectively in 94 consecutive patients attending the diabetes antenatal clinic and compared to the corresponding mean HbA1c levels. RESULTS: There was a significant linear correlation between mean HBG and HbA1c (HbA1c=0.5HBG+3.1, r=0.71, p<0.0001). Multiple regression analysis demonstrated that both pre- and post-prandial HBG levels correlated significantly and independently with HbA1c, correlation coefficients (r) were 0.63 and 0.65, respectively both p<0.0001. Significant correlations were also observed in patients with gestational diabetes (n=67, mean HbA1c=6.11, r=0.67; p<0.0001) and type 1 diabetes (n=18, mean HbA1c=6.75, r=0.64; p=0.004). All meal related HBG measurements showed similar significant correlations with HbA1c (r values pre- and post-breakfast, pre- and post-lunch, pre- and post-tea and pre-bed are 0.56, 0.55, 0.59, 0.55, 0.56, 0.59, 0.51, respectively p<0.0001 for all time points). Post hoc analysis showed that NBW increased with higher levels of HbA1c; NBW (centiles)+/-S.D. for HbA1c <6.5% versus >6.5% was 78.9%+/-29.2 versus 90.2%+/-18.6, p=0.02. CONCLUSION: Mean HbA1c levels are closely correlated to all meal related glucose measurements during pregnancy. It is therefore a reliable indicator of overall glycaemic control among patients with diabetes during pregnancy.
Assuntos
Peso ao Nascer , Glicemia/análise , Diabetes Gestacional/sangue , Hemoglobinas Glicadas/análise , Gravidez em Diabéticas/sangue , Gravidez/sangue , Automonitorização da Glicemia , Feminino , Humanos , Recém-Nascido , Período Pós-Prandial , Estudos RetrospectivosRESUMO
OBJECTIVE: A decline in the function of all organs can be detected during ageing. Although the trend appears to be stable, deviation within the elderly population is much greater in comparison to young controls. The aim of the study was to identify a marker of senescence which correlates to heart function. Advanced glycation endproducts (AGEs) accumulate with age and are associated with degenerative diseases. METHODS: Carboxymethyllysine (CML) concentrations in the pericardial fluid (as a measure of AGEs) were analysed with ELISA technique in 75 patients undergoing cardiac surgery and correlated with clinical parameters and outcome of these patients. RESULTS: CML content of pericardial fluid increases significantly with age. AGEs show an inverse correlation to left ventricular ejection fraction. High CML levels correlate with poor outcome of patients as shown by adverse cardiac events, prolonged ventilation time and prolonged stay within the Intensive Care Unit. Within all parameters, AGE concentration of the pericardial fluid fits better with the outcome of the patients in comparison to age alone. Interestingly, medical treatment with nitrates correlates with increased CML content. CONCLUSION: AGEs, in addition to being a marker of senescence, appear to represent a prognostic factor in cardiac surgery, which can be used as a predictor of patient outcome.
Assuntos
Envelhecimento/fisiologia , Biomarcadores/análise , Ponte de Artéria Coronária , Produtos Finais de Glicação Avançada/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Coração/crescimento & desenvolvimento , Coração/fisiologia , Humanos , Lisina/análogos & derivados , Lisina/análise , Pessoa de Meia-Idade , Derrame Pericárdico/fisiopatologia , Valor Preditivo dos Testes , Resultado do TratamentoRESUMO
Eukaryotic expression vectors can be delivered to macrophages using attenuated self-destructing Listeria monocytogenes. L. monocytogenes cells are preferentially lysed in the host cell macrophage cytosol by the production of a PactA-dependent Listeria-specific phage lysin. Efficient expression of the cloned reporter genes by the macrophages and subsequent antigen presentation were achieved after the delivery of eukaryotic expression vectors by the attenuated suicide L. monocytogenes strain. After delivery by L. monocytogenes plasmid DNAs were found to integrate into the macrophage cell's genome at a frequency of about 10(-7).
Assuntos
Vetores Genéticos , Listeria monocytogenes/genética , Macrófagos/metabolismo , Plasmídeos/genética , Vacinas de DNA , Animais , Vacinas Bacterianas , Bacteriólise , Bacteriófagos/enzimologia , Bacteriófagos/genética , Citomegalovirus/genética , Citosol/metabolismo , Endopeptidases/genética , Endopeptidases/metabolismo , Genes Reporter , Listeria monocytogenes/virologia , Camundongos , Camundongos Endogâmicos BALB C , Regiões Promotoras Genéticas , Células Tumorais Cultivadas , Vacinas AtenuadasRESUMO
BACKGROUND: Angiotensin II activates 2 distinct G protein-coupled receptors, the AT(1) and AT(2) receptors. Most of the known cardiovascular effects of angiotensin II are mediated by the AT(1) receptor subtype. The aim of the present study was to test whether deletion of the AT(2) receptor gene in mice (AT(2)-KO mice) leads to long-term functional or structural alterations in the cardiovascular system. METHODS AND RESULTS: In vivo pressure responses to angiotensin II or the alpha(1)-adrenergic receptor agonist phenylephrine were greatly enhanced in AT(2)-KO mice. Deletion of the angiotensin AT(2) receptor did not lead to a compensatory increase of the activity of the circulating renin-angiotensin system, and arterial blood pressure was identical in wild-type control mice (WT) and AT(2)-KO mice. Cardiac contractility as assessed by LV catheterization and by rapid MRI also did not differ between AT(2)-KO and WT mice. Isolated femoral arteries from AT(2)-KO mice, however, showed enhanced vasoconstriction to angiotensin II, norepinephrine, and K(+) depolarization compared with WT. Morphometric analysis of large and small femoral arteries revealed a significant hypertrophy of media smooth muscle cells. Phospho-P70S6 kinase levels were significantly increased in aortas from AT(2)-KO mice compared with WT mice. Treatment of mice with an ACE inhibitor for 8 weeks abolished the increased pressure responsiveness, vascular hypertrophy, and enhanced P70S6 kinase phosphorylation in AT(2)-KO mice. CONCLUSIONS: These results indicate that vascular AT(2) receptors inhibit the activity and, hence, hypertrophic signaling by the P70S6 kinase in vivo and thus are important regulators of vascular structure and function.
Assuntos
Receptores de Angiotensina/genética , Receptores de Angiotensina/fisiologia , Proteínas Quinases S6 Ribossômicas/metabolismo , Doenças Vasculares/etiologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Pressão Sanguínea , Captopril/farmacologia , Técnicas de Cultura , Coração/fisiopatologia , Hemodinâmica , Hipertrofia/etiologia , Hipertrofia/patologia , Hipertrofia/fisiopatologia , Imageamento por Ressonância Magnética , Camundongos , Camundongos Knockout , Miografia , Fosforilação , Receptor Tipo 2 de Angiotensina , Transdução de Sinais , Doenças Vasculares/patologia , Doenças Vasculares/fisiopatologia , VasoconstriçãoRESUMO
OBJECTIVE: Primary cardiac myocyte cultures are usually contaminated with variable parts of different cell types, such as fibroblasts, endothelial cells and smooth muscle cells. Thus, the objective of our study was to analyse the gene expression in a pure population. METHODS: To obtain an homogeneous population, cardiac myocytes from adult rats were fixed with ethanol and sorted by flow cytometry. This approach is suitable for isolating either single cells or up to several thousand cells. To measure the messenger ribonucleic acid (mRNA) expression of different genes at the level of a few rod-shaped myocytes, a cDNA library was created by polymerase chain reaction (PCR). RESULTS: Sorting by a fluorescence-activated cell sorter (FACS) resulted in pure rod-shaped cardiac myocytes and isolated RNA from these cells is undegraded, as shown by Northern blotting. We demonstrated both the expression of housekeeping genes, such as beta-actin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as well as the myocyte-specific transcripts, alpha-cardiac myosin heavy chain (alpha-MHC) and beta-MHC. Furthermore, we showed the induction of the immediately early gene c-fos at the level of ten sorted cells. CONCLUSIONS: This method allows one to study gene expression in different cell types within the heart, in tissue samples or to tackle the problem of heterogeneity within a cell population.
Assuntos
Miocárdio/citologia , Miocárdio/metabolismo , Animais , Northern Blotting , Separação Celular , Tamanho Celular , Primers do DNA , Citometria de Fluxo/métodos , Expressão Gênica , Imuno-Histoquímica , Masculino , RNA Mensageiro/análise , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVE: Cardiovascular diseases are the leading cause of death in the Western World, especially in the elder population. One pathophysiological component of cardiovascular disease is myocardial fibrosis, primarily derived from cardiac fibroblasts. Here we investigated the regulation of proliferation of fibroblasts from hearts of adult rats by platelet derived growth factor AA (PDGF-AA). METHODS: Cardiac fibroblasts were isolated from adult Wistar rats. PDGF-induced cell proliferation was analysed by FACS. PDGF-receptor numbers were analysed by receptor binding assays. Using differential display, differentially expressed kinases were identified during ageing in vitro and confirmed by Northern and Western blotting. Transient overexpression of IRES-GFP constructs was used to analyse the role of the akt kinase on proliferation by FACS. RESULTS: During in vitro senescence/aging of primary fibroblasts, the growth response to PDGF-AA was greatly reduced without alterations in its receptor number or affinity and without changes in downstream signalling via the MAP-kinase pathway. By using a differential display strategy selective for protein kinases, we identified reduced expression of Akt-1 kinase (PKB-alpha) in senescent rat cardiac fibroblasts. These findings were supported by data showing reduced expression of Akt-1 in heart samples from old humans. Overexpression of activated Akt-1 almost completely reconstituted PDGF-AA dependent cell proliferation in aged fibroblasts. CONCLUSION: These results support an important role for Akt in senescence and regulation of cardiac fibroblast cell proliferation.
Assuntos
Fibroblastos/metabolismo , Miocárdio/enzimologia , Miocárdio/patologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas , Animais , Becaplermina , Northern Blotting , Western Blotting , Divisão Celular/efeitos dos fármacos , Senescência Celular , Depressão Química , Fibrose , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas c-sis , Ratos , Ratos Wistar , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
OBJECTIVE: The aim was to study the L-type calcium current (ICa,L) in cardiac myocytes as a possible target of insulin in the regulation of cardiac function. METHOD: Using the whole-cell configuration of the patch-clamp technique, we investigated the stimulation of ICa,L by insulin in isolated rat ventricular myocytes. RESULTS: The stimulation of ICa,L by insulin was dose-dependent (EC50 = 33 nM) and reversible. Maximum stimulation of ICa,L over basal ICa,L was 86 +/- 11% (n = 25) at 1 microM insulin. Insulin (1 microM) shifted the current-voltage relationship and potential-dependent availability of ICa,L to more negative potentials by about 3.5 and 1.5 mV, respectively. The maximum conductance of ICa,L was increased by 1 microM insulin, from 26 +/- 4 to 39 +/- 5 nS (n = 11). Isoproterenol (100 nM), which stimulated ICa,L by 156 +/- 23% (n = 10) over basal ICa,L, acted faster than insulin. The half-maximum stimulation of ICa,L by isoproterenol and insulin was reached after 44 +/- 5 and 80 +/- 9 s, respectively. Insulin and isoproterenol responses were not additive. Insulin (1 microM) and isoproterenol (100 nM) stimulation of ICa,L was inhibited by Rp-cAMPS (1 mM) to 12 +/- 3 and 32 +/- 4%, respectively. Insulin (1 microM) increased cAMP content in rat cardiomyocytes by about two-fold. Insulin-like growth factor-1 (IGF-1; 5 microM) increased ICa,L by only 5.9 +/- 0.9% (n = 6). CONCLUSIONS: Our data show that insulin stimulates the L-type calcium current in isolated rat ventricular myocytes in a dose-dependent and reversible manner and suggest that this effect is mediated by insulin receptors and the cAMP-dependent protein kinase.
Assuntos
ATPases Transportadoras de Cálcio/efeitos dos fármacos , Insulina/farmacologia , Miocárdio/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , AMP Cíclico/análogos & derivados , AMP Cíclico/metabolismo , AMP Cíclico/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Isoproterenol/farmacologia , Técnicas de Patch-Clamp , Ratos , Estimulação Química , Tionucleotídeos/farmacologiaRESUMO
OBJECTIVE: The L-type calcium current (ICa,L) in isolated human atrial myocytes was investigated as a possible target of insulin in the regulation of cardiac function. METHODS: Atrial myocytes were obtained from patients undergoing cardiac surgery. Using the whole-cell configuration of the patch-clamp technique, we investigated the stimulation of ICa,L by insulin in single human atrial myocytes. RESULTS: We found a dose-dependent stimulation of ICa,L by insulin at concentrations of 100 nM, 1 microM and 10 microM. Maximum stimulation of ICa,L over basal ICa,L was 140 +/- 12% (n = 11) at 10 microM insulin. The maximum conductance of ICa,L was increased by 10 microM insulin from 4.0 +/- 0.3 nS to 8.3 +/- 1.0 nS (n = 6). The stimulation of ICa,L by insulin was dose-dependent and reversible. Isoproterenol (10 nM) that stimulates ICa,L by 271 +/- 48% (n = 10) over basal ICa,L acted faster than insulin. The half-maximum stimulation of ICa,L by isoproterenol and insulin (10 microM) was reached after 31 +/- 2 s and 52 +/- 5 s, respectively. The insulin effect shown was totally reversed by acetylcholine (3 microM) which is known to inhibit adenylyl cyclase activity/cAMP-production via Gi-proteins. Also, the selective insulin receptor tyrosine kinase inhibitor (hydroxy-2-naphthanelyl-methyl)phosphonic acid completely inhibited the insulin induced effect. CONCLUSION: Our data show that insulin stimulates the L-type calcium current in isolated human atrial myocytes in a dose-dependent and reversible manner which appears to involve the insulin receptor tyrosine kinase. Insulin regulation of ICa,L in human atrial myocytes may be an interesting system for the analysis of the metabolic syndrome in man.
Assuntos
Canais de Cálcio Tipo L/metabolismo , Insulina/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Miocárdio/metabolismo , Acetilcolina/farmacologia , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Criança , Relação Dose-Resposta a Droga , Feminino , Átrios do Coração , Humanos , Isoproterenol/farmacologia , Masculino , Pessoa de Meia-Idade , Organofosfonatos/farmacologia , Técnicas de Patch-Clamp , Receptor de Insulina/antagonistas & inibidores , Estimulação Química , Fatores de TempoRESUMO
AIM: During ageing, advanced glycation end-products (AGEs) accumulate in extracellular matrix proteins like collagen and contribute to a decline in organ function. As skin autofluorescence (sAF) can assess subcutaneous accumulation of fluorescent AGEs, this study aimed to investigate the relationship between AGE-modified cardiac tissue collagen and AGE-related sAF in coronary artery bypass graft (CABG) surgery patients. METHODS: Between January 2011 and January 2012, data from 72 consecutive male patients undergoing isolated CABG were prospectively recorded. Collagen fractions were isolated from the right atrial appendages of these patients by proteolysis and collagenase digestion. Collagen was quantified by hydroxyproline assay, and AGEs by AGE-related intrinsic fluorescence; sAF was measured using an autofluorescence reader. RESULTS: Biochemical analysis showed that the insoluble cardiac collagen fraction contained the highest amounts of accumulated AGEs; the AGE-related intrinsic fluorescence of this fraction increased with age (P=0.0001), blood glucose (P=0.002), HbA1c (P=0.01) and sAF (P=0.008). CONCLUSION: This study demonstrated for the first time a relationship between cardiac tissue glycation and AGE-related sAF. In addition, cardiac tissue glycation was associated with age, blood glucose and long-term glucose values in patients with coronary artery disease.