RESUMO
BACKGROUND AND PURPOSE: Life style-related disorders such as hypertension, diabetes, dyslipidemia, and obesity are reported to be a great risk of dementia. Adipocytokines released from adipose tissue are thought to modulate some brain functions including memory and cognition. We here analysed adiponectin, one of the most important adipocytokines, in plasma and cerebrospinal fluid (CSF) from cognitive normal controls (NC), mild cognitive impairment (MCI) subjects, and patients with Alzheimer's disease (AD) and discussed if/how adiponectin could relate to the pathogenesis of AD. METHODS: Normal controls (n = 28), MCI (n = 18), and AD (n = 27) subjects were recruited at Tohoku University Hospital. The diagnosis of AD was based on NINCDS-ADRDA criteria. All the blood and CSF samples were obtained from each fasted subject. Adiponectin was assayed using a sandwich ELISA system. RESULTS: The levels of adiponectin between in plasma and in CSF showed a positive correlation. Plasma adiponectin was significantly higher in MCI and AD compared to NC, whereas CSF adiponectin was significantly higher in MCI compared to NC. CONCLUSION: It is possible that the level of adiponectin in plasma reflects its level in CSF. The tendency to have higher adiponectin in plasma and CSF from MCI and AD suggests that this molecule plays a critical role in the onset of AD.
Assuntos
Adiponectina/sangue , Adiponectina/líquido cefalorraquidiano , Doença de Alzheimer/sangue , Doença de Alzheimer/líquido cefalorraquidiano , Transtornos Cognitivos/sangue , Transtornos Cognitivos/líquido cefalorraquidiano , Idoso , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Testes NeuropsicológicosRESUMO
BACKGROUND: Oxidative stresses including cigarette smoking are implicated in the pathogenesis of cerebrovascular diseases, which are associated with pneumonia because of frequent aspiration. Haem oxygenase-1 (HO-1) acts in cytoprotection against oxidants, provides anti-inflammatory effects, and inhibits atherogenesis. A (GT)(n) dinucleotide repeat in the human HO-1 promoter modulates HO-1 gene expression and shows length polymorphism, which is grouped into three classes: class S (<27 repeats), class M (> or = 27, <33 repeats), and class L (> or = 33 repeats) alleles. OBJECTIVE: To investigate the correlation between the HO-1 gene polymorphism and development of pneumonia in elderly Japanese. METHODS: The length of the (GT)n repeats was analysed in 200 elderly patients with pneumonia and 200 control subjects. The association of the HO-1 gene polymorphism with risk of pneumonia was estimated by logistic regression. RESULTS: The proportion of allele frequencies in class L, and the proportion of genotypic frequencies in the L-allele carriers (L/L, L/M, and L/S), was significantly higher in patients with pneumonia than in controls (20% v 10% in class L, and 34% v 18% in L-allele carriers). After adjustment for potentially confounding factors, both cerebrovascular disorders and HO-1 gene L-allele carriers were significant and independent risk factors for pneumonia. The adjusted odds ratio for L-allele carriers v non-L-allele carrier was 2.1 (95% confidence interval, 1.2 to 3.6). CONCLUSIONS: The large size of a (GT)n repeat in the HO-1 gene promoter may be associated with susceptibility to pneumonia in the older Japanese population.
Assuntos
Povo Asiático/genética , Predisposição Genética para Doença , Heme Oxigenase-1/genética , Pneumonia/genética , Polimorfismo Genético , Idoso , Carboxihemoglobina/metabolismo , Feminino , Frequência do Gene , Testes Genéticos , Humanos , Japão , Masculino , Pneumonia/epidemiologia , Regiões Promotoras Genéticas , Fatores de RiscoRESUMO
Interleukin (IL)-28A/interferon (IFN)-λ2 and IL-29/IFN-λ1 have been demonstrated to elicit direct and indirect anti-tumor actions. In this study, we constructed an adenovirus vector expressing either IL-28A/IFN-λ2 (AdIL-28A) or IL-29/IFN-λ1 (AdIL-29) to evaluate the therapeutic properties of intratumoral injection of recombinant adenovirus to apply for the clinical implementation of cancer gene therapy. Despite the lack of an anti-proliferative effect on MCA205 and B16-F10 cells, a retarded growth of established subcutaneous tumors was observed following multiple injections of either AdIL-28A or AdIL-29 when compared with AdNull. In vivo cell depletion experiments displayed that both NK cells and CD8(+) T cells have a major role in AdIL-28A-mediated tumor growth suppression. A significant increase in the number of infiltrating CD8(+) T cells into the tumors treated with either AdIL-28A or AdIL-29 was observed. Moreover, specific anti-tumor cytotoxic T lymphocyte reactivity was detected in spleen cells from animals treated with either AdIL-28A or AdIL-29. In IFN-γ-deficient mice, anti-tumor activities of AdIL-28A were completely impaired, indicating that IFN-γ is critically involved in the tumor growth inhibition triggered by AdIL-28A. IL-12 provided a synergistic anti-tumor effect when combined with AdIL-28A. These results indicate that AdIL-28A and AdIL-29 could be successfully utilized as an alternative cancer immunogene therapy.
Assuntos
Adenoviridae/genética , Terapia Genética , Vetores Genéticos/genética , Imunomodulação/genética , Neoplasias/genética , Neoplasias/imunologia , Transgenes , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Expressão Gênica , Vetores Genéticos/administração & dosagem , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Injeções Intralesionais , Interferon gama/biossíntese , Interferons/genética , Interferons/metabolismo , Interleucina-12/farmacologia , Interleucinas/genética , Interleucinas/metabolismo , Melanoma Experimental , Camundongos , Camundongos Knockout , Neoplasias/patologia , Neoplasias/terapia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Transdução Genética , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/genética , Carga Tumoral/imunologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
1. The airway and pulmonary vascular effects of adrenomedullin were studied in the guinea-pig isolated trachea, main bronchi and pulmonary artery in vitro and compared to the effects of calcitonin gene-related peptide (CGRP). 2. In tracheal rings, CGRP (1 nM to 1 microM) potentiated the cholinergic contractions induced by electrical field stimulation (EFS) at 5 Hz in a concentration-dependent manner. At a concentration of 1 microM, CGRP slightly decreased the responses to log EFS frequency, producing 50% of the maximum contraction from a control value of 0.77 +/- 0.10 Hz to 0.54 +/- 0.05 Hz without a significant effect on the concentration-response curves to acetylcholine (ACh). In contrast, adrenomedullin (1 nM to 1 microM) did not alter either EFS-induced cholinergic or ACh-induced contractions. 3. In bronchial strips, CGRP (1 nM to 1 microM) slightly reduced both the non-adrenergic non-cholinergic (NANC) contraction induced by EFS at 10 Hz and the substance P (1 microM)-induced contraction in a concentration-dependent manner, whereas adrenomedullin (1 nM to 1 microM) was without effect. 4. Neither CGRP (1 microM) nor adrenomedullin (1 microM) altered NANC relaxation induced by EFS at 5 Hz in tracheal rings precontracted with histamine (10 microM). 5. Adrenomedullin (1 nM to 1 microM) and CGRP (1 nM to 1 microM) induced a concentration-dependent relaxation of the histamine (10 microM)- and prostaglandin F2 alpha (10 microM)-precontracted pulmonary arterial rings with intact endothelium with a similar potency. 6. Neither removal of the endothelium nor NG-nitro-L-arginine methyl ester (100 microM) altered the vasorelaxant effects of adrenomedullin (1 nM to 1 microM) and CGRP (1 nM to 1 microM). 7. The putative CGRP receptor antagonist, CGRP8-37 (1 microM to 10 microM) concentration-dependently attenuated the CGRP (3 nM to 30 nM)-induced vasorelaxant actions, whereas it had no effect on the relaxation of vessel rings induced by adrenomedullin (3 nM to 30 nM). 8. These results suggest that adrenomedullin is a potent vasodilator of the pulmonary artery without any bronchomotor effect in the guinea-pig lung, and that the vasorelaxant actions of adrenomedullin are not mediated via the activation of CGRP1 receptors.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Peptídeos/farmacologia , Vasodilatadores/farmacologia , Adrenomedulina , Animais , Vias Autônomas/efeitos dos fármacos , Brônquios/efeitos dos fármacos , Brônquios/inervação , Antagonistas do Receptor do Peptídeo Relacionado ao Gene de Calcitonina , Estimulação Elétrica , Inibidores Enzimáticos/farmacologia , Cobaias , Técnicas In Vitro , Masculino , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/inervação , Músculo Liso Vascular/inervação , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Sistema Nervoso Parassimpático/efeitos dos fármacos , Sistema Nervoso Parassimpático/fisiologia , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/inervação , Traqueia/efeitos dos fármacos , Traqueia/inervaçãoRESUMO
PURPOSE: The respiratory aspiration of the stomach contents causes severe lung damage called aspiration pneumonia. The present study was undertaken to elucidate whether mucosal exposure of gastric juice causes hyperpermeability of the human airway epithelium and to determine the mechanisms responsible for gastric juice-induced airway epithelial damage. MATERIALS AND METHODS: Gastric juice was collected from 46 normal adults via gastroscope and samples were analyzed for pH, osmolarity, and concentration of pepsin and trypsin. Tracheal surface epithelial cells were obtained from 16 autopsies, cultured onto porous filters, and mounted in the Ussing chamber. Electrical conductance (G) was measured before and after exposure of cells to gastric juice or Krebs-Henseleit solution with pH at 1.8, 2.8, 4.0, or 7.4 in the presence or absence of pepsin. D-[3H] mannitol flux study across the epithelial layer and histologic observations using an inverted microscope were also performed after exposure of cells to gastric juice. RESULTS: Exposure of cultured human tracheal epithelium to gastric juice caused increases in G in a time- and pH-dependent fashion. A pepsin inhibitor (pepstatin A) inhibited gastric juice-induced increases in G at a pH of 2.8, and the addition of pepsin augmented increases in G induced by the Krebs-Henseleit solution at a pH of 1.8 and 2.8. Lowering the osmolarity of the solution to levels similar to gastric juice also potentiated increases in G induced by acid and pepsin. Gastric juice caused increases in D-[3H] mannitol flux across the epithelial layer bidirectionally, and microscopic observation revealed separation of the intercellular space and cell detachment from culture vessels after exposure of cells to gastric juice. CONCLUSION: Gastric juice causes hyperpermeability across human airway epithelium probably through the additive effects of gastric acid, pepsin activity, and lower osmolarity.
Assuntos
Permeabilidade da Membrana Celular/fisiologia , Suco Gástrico/fisiologia , Traqueia/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Epitélio/patologia , Epitélio/fisiologia , Suco Gástrico/química , Humanos , Concentração de Íons de Hidrogênio , Pessoa de Meia-Idade , Concentração Osmolar , Pepsina A/fisiologia , Traqueia/citologiaRESUMO
Pneumonia is a common cause of death in older people. Antimicrobial drugs do not prevent pneumonia and, because of increasingly resistant organisms, their value in curing infection will become more limited. Establishing new strategies to prevent pneumonia through consideration of the mechanisms of this devastating illness is essential. The purpose of this review is to discuss how pneumonia develops in older people and to suggest preventive strategies that may reduce the incidence of pneumonia among older adults. Aspiration of oropharyngeal bacterial pathogens to the lower respiratory tract is one of the most important risk factors for pneumonia; impairments in swallowing and cough reflexes among older adults, e.g., related to cerebrovascular disease, increase the risk for the development of pneumonia. Thus, strategies to reduce the volumes and pathogenicity of aspirated material should be pursued. For example, since both swallowing and cough reflexes are mediated by endogenous substance P, pharmacologic therapy using angiotensin-converting enzyme inhibitors, which decrease substance P catabolism, may improve both reflexes and result in the lowering of the risk of pneumonia. Similarly, since the production of substance P is regulated by dopaminergic neurons in the cerebral basal ganglia, treatment with dopamine analogs or potentiating drugs such as amantadine (and, of course, prevention of cerebral vascular disease, which can result in basal ganglia strokes) should affect the incidence of pneumonia. The purpose of this review is to consider promising pharmacologic treatments as methods of preventing pneumonia in older adults and to review other proven strategies, e.g., infection control and cerebrovascular disease prevention that will lessen the incidence of pneumonia.
Assuntos
Pneumonia Aspirativa/etiologia , Pneumonia/etiologia , Idoso , Amantadina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Transtornos Cerebrovasculares/prevenção & controle , Refluxo Gastroesofágico/prevenção & controle , Humanos , Controle de Infecções , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Levodopa/uso terapêutico , Higiene Bucal , Vacinas Pneumocócicas/administração & dosagem , Pneumonia/prevenção & controle , Pneumonia Aspirativa/prevenção & controle , Fatores de Risco , Substância P/antagonistas & inibidoresRESUMO
To partition the central and peripheral airway resistance in awake humans, a catheter-tipped micromanometer sensing lateral pressure of the airway was wedged into the right lower lobe of a 3-mm-ID bronchus in 5 normal subjects, 7 patients with chronic bronchitis, 8 patients with emphysema, and 20 patients with bronchial asthma. We simultaneously measured mouth flow, transpulmonary pressure, and intra-airway lateral pressure during quiet tidal breathing. Total pulmonary resistance (RL) was calculated from transpulmonary pressure and mouth flow and central airway resistance (Rc) from intra-airway lateral pressure and mouth flow. Peripheral airway resistance (Rp) was obtained by the subtraction of Rc from RL. The technique permitted identification of the site of airway resistance changes. In normal subjects, RL was 3.2 +/- 0.2 (SE) cmH2O.l-1.s and the ratio of Rp to RL was 0.24 during inspiration. Patients with bronchial asthma without airflow obstruction showed values of Rc and Rp similar to those of normal subjects. Although Rc showed a tendency to increase, only Rp significantly increased in those patients with bronchial asthma with airflow obstruction and patients with chronic bronchitis and emphysema. The ratio of Rp to RL significantly increased in three groups of patients with airflow obstruction (P less than 0.01). These observations suggest that peripheral airways are the predominant site of airflow obstruction, irrespective of the different pathogenesis of chronic airflow obstruction.
Assuntos
Resistência das Vias Respiratórias/fisiologia , Pneumopatias/fisiopatologia , Adulto , Idoso , Asma/fisiopatologia , Bronquite/fisiopatologia , Enfisema/fisiopatologia , Feminino , Humanos , Pneumopatias Obstrutivas/fisiopatologia , Masculino , Manometria/instrumentação , Pessoa de Meia-Idade , Testes de Função RespiratóriaRESUMO
This paper describes a method for measuring the increase in halide permeability of isolated airway epithelial cells induced by adenosine 3',5'-cyclic monophosphate (cAMP). Suspensions of isolated cells, known to contain the cystic fibrosis transmembrane conductance regulator (CFTR), were placed in the upper part of a Swinnex filter holder containing a filter with pores of 0.65 micron diameter. Medium was perfused over the cells at room temperature and collected at minute intervals following its passage through the filter. Experiments were performed on Calu-3 and T84 cells (human lung and colonic epithelial cell lines), primary cultures of dog and human tracheal epithelium, and Swiss 3T3 fibroblasts stably transfected with CFTR. In all cell types, addition of agents that elevate cAMP led to increases in the rates of loss of 36Cl and 125I. However, in human tracheal epithelial cells, warming the medium from room temperature to 37 degrees C was a more effective way of stimulating tracer efflux. Increases in efflux in response to either temperature or cAMP-elevating agents were inhibited by diphenylamine-2-carboxylate, a blocker of CFTR. Reproducible increases in tracer efflux were seen with as few as 10(6) cells. Cells that had been trypsinized off their culture dishes responded better than cells that had been scraped off, although treatment of scraped cells with trypsin enhanced their responsiveness to cAMP-elevating agents. Cystic fibrosis is characterized by the lack of a cAMP-activated Cl conductance in the apical membrane of airway epithlia.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Cloretos/metabolismo , Fisiologia/métodos , Traqueia/metabolismo , Animais , Permeabilidade da Membrana Celular , Cloro , AMP Cíclico/fisiologia , Regulador de Condutância Transmembrana em Fibrose Cística , Cães , Eletrofisiologia , Células Epiteliais , Epitélio/metabolismo , Epitélio/fisiologia , Humanos , Radioisótopos do Iodo , Proteínas de Membrana/metabolismo , Fisiologia/instrumentação , Radioisótopos , Traqueia/citologia , Traqueia/fisiologiaRESUMO
To determine whether O3 exposure increased airway responsiveness to antigen inhalation, we studied airway responsiveness to acetylcholine (ACh) and Ascaris suum antigen (AA) before and after O3 in dogs both sensitive and insensitive to AA. Airway responsiveness was assessed by determining the provocative concentration of ACh and AA aerosols that increased respiratory resistance (Rrs) to twice the base-line value. O3 (3 parts per million) increased airway responsiveness to ACh in dogs both sensitive and insensitive to AA, and it significantly decreased the ACh provocation concentration from 0.541 +/- 0.095 to 0.102 +/- 0.047 (SE) mg/ml (P less than 0.01; n = 10). AA aerosols, even at the highest concentration in combination with O3, did not increase Rrs in dogs insensitive to AA. However, O3 increased airway responsiveness to AA in AA-sensitive dogs and significantly decreased log AA provocation concentration from 2.34 +/- 0.22 to 0.50 +/- 0.17 (SE) log protein nitrogen units/ml (P less than 0.01; n = 7). O3-induced hyperresponsiveness to ACh returned to the base-line level within 2 wk, but hyperresponsiveness to AA continued for greater than 2 wk. The plasma histamine concentration after AA challenge was significantly higher after than before O3 (P less than 0.01). Intravenous infusion of OKY-046 (100 micrograms.kg-1.min-1), an inhibitor of thromboxane synthesis, inhibited the O3-induced increase in responsiveness to ACh, but it had no effects on the O3-induced increase in responsiveness to AA and the increase in the plasma histamine concentration. These results suggest that O3 increases susceptibility to the antigen in sensitized dogs via a different mechanism from that of O3-induced muscarinic hyperresponsiveness.
Assuntos
Resistência das Vias Respiratórias/efeitos dos fármacos , Antígenos de Helmintos/administração & dosagem , Ozônio/toxicidade , Acetilcolina/farmacologia , Aerossóis , Resistência das Vias Respiratórias/imunologia , Animais , Ascaris/imunologia , Asma/etiologia , Cães , Feminino , Histamina/sangue , Masculino , Metacrilatos/farmacologia , Testes Cutâneos , Tromboxano-A Sintase/antagonistas & inibidoresRESUMO
To examine muscarinic receptor subtypes involved in cholinergically mediated contractions of the airway, we studied the effects of the M1-selective antagonist, pirenzepine, the M2-selective antagonist, AF-DX 116, the M3-selective antagonist, 4-diphenyl-acetoxy-N-methylpiperidine (4-DAMP) methiodide, and the non-selective antagonist, atropine, on acetylcholine (ACh)- and electrically induced contractions in dog bronchi and bronchioles. The relative potencies of the antagonists based on IC50 values of each antagonist for contractions induced by the two concentrations of ACh that produced 50% of the maximum (ED50) and the maximum (EDmax) contractions and the pA2 values were atropine greater than or equal to 4-DAMP methiodide greater than pirenzepine = AF-DX 116 in both the bronchi and bronchioles. The IC50 and pA2 values of each antagonist did not differ significantly between the bronchi and bronchioles. 4-DAMP methiodide significantly inhibited the contractile response to electrical field stimulation (EFS) at 5 Hz at concentrations that did not alter the contractile responses to exogenous ACh in both the bronchi and bronchioles, whereas pirenzepine, AF-DX 116 and atropine inhibited the EFS-induced contraction only at the concentrations that reduced the contraction induced by exogenous ACh. The present results suggest that the cholinergic contraction is mediated via the postsynaptic receptor M3, based on functional potencies of muscarinic antagonists and presynaptic receptor auto-facilitatory M3, based on the suppression of the contractile response to EFS by 4-DAMP methiodide in central and peripheral airways.
Assuntos
Atropina/farmacologia , Brônquios/fisiologia , Contração Muscular/efeitos dos fármacos , Parassimpatolíticos/farmacologia , Piperidinas/farmacologia , Pirenzepina/análogos & derivados , Pirenzepina/farmacologia , Receptores Muscarínicos/fisiologia , Acetilcolina/farmacologia , Animais , Brônquios/efeitos dos fármacos , Cães , Relação Dose-Resposta a Droga , Estimulação Elétrica , Técnicas In Vitro , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Receptores Muscarínicos/efeitos dos fármacos , Receptores Muscarínicos/metabolismoRESUMO
To determine whether neurogenic inflammation can be inhibited by prostaglandin E1 (PGE1), that is suggested to have an inhibitory effect on neuropeptide release from airway sensory nerves, we examined plasma extravasation in the airways of anesthetized rats in vivo with Evans blue due as a marker. Neurogenic inflammation was produced by an i.v. injection of capsaicin (100 micrograms/kg) or by antidromic electrical stimulation of the right vagus nerve (4 Hz, 1 ms, 4 V for 1 min). Capsaicin injection significantly increased leakage of dye in the trachea and main bronchi. Similar increases in leakage were seen in the trachea and right bronchus on electrical stimulation of the right vagus nerve. PGE1 (1-1000 micrograms/kg) inhibited the leakage induced by capsaicin in the trachea and bronchi concentration dependently with complete inhibition at a concentration of 1000 micrograms/kg. Likewise, PGE1 (1000 micrograms/kg) significantly inhibited electrical stimulation-induced leakage in the trachea and right bronchus (P less than 0.01). I.v. substance P (SP; 1 microgram/kg) increased Evans blue dye extravasation in the same way as the leakage induced by capsaicin and electrical stimulation but PGE1 (1000 micrograms/kg) failed to inhibit SP-induced leakage in the trachea and main bronchi (P greater than 0.20). These results suggest that PGE1 inhibits neurogenic plasma leakage by presynaptic inhibition of the release of neuropeptides from sensory nerves.
Assuntos
Alprostadil/uso terapêutico , Brônquios/irrigação sanguínea , Extravasamento de Materiais Terapêuticos e Diagnósticos/prevenção & controle , Neurite (Inflamação)/sangue , Traqueia/irrigação sanguínea , Animais , Proteínas Sanguíneas/metabolismo , Brônquios/inervação , Capsaicina/farmacologia , Estimulação Elétrica , Azul Evans/farmacocinética , Extravasamento de Materiais Terapêuticos e Diagnósticos/etiologia , Neurite (Inflamação)/induzido quimicamente , Neurite (Inflamação)/prevenção & controle , Ratos , Ratos Sprague-Dawley , Substância P/farmacologia , Traqueia/inervação , Nervo Vago/efeitos dos fármacos , Nervo Vago/fisiologiaRESUMO
We have investigated the role of carbon monoxide (CO) in lucigenin-dependent chemiluminescence of alveolar macrophages from rat lungs. CO (10 nM to 1 microM) decreased chemiluminescence of alveolar macrophages in a concentration-dependent fashion. At a concentration of 1 microM, CO significantly increased intracellular cyclic GMP levels from a control value of 175 +/- 25 fmol/2 x 10(6) cells to 431 +/- 49 fmol/2 x 10(6) cells. Pretreatment of alveolar macrophages with NG-monomethyl-L-arginine (100 microM) failed to inhibit CO (1 microM)-induced decreases in chemiluminescence of alveolar macrophages (3.7 +/- 0.7 cpm x 10(3) in the presence of NG-monomethyl-L-arginine and 3.4 +/- 0.6 cpm x 10(3) in the absence of NG-monomethyl-L-arginine) and CO (1 microM)-induced increases in intracellular cyclic GMP levels (452 +/- 65 fmol/2 x 10(6) cells in the presence of NG-monomethyl-L-arginine and 419 +/- 58 fmol/2 x 10(6) cells in the absence of NG-monomethyl-L-arginine). Decreases in chemiluminescence of alveolar macrophages induced by CO (1 microM) were concentration-dependently inhibited by methylene blue (from 0.1 microM to 10 microM). Dibutyryl cyclic GMP (db cyclic GMP) (1 mM) also reduced chemiluminescence of alveolar macrophages (1.5 +/- 0.3 cpm x 10(3) in the presence of db cyclic GMP and 3.6 +/- 0.6 cpm x 10(3) in the absence of db cyclic GMP). In contrast to CO and db cyclic GMP, zinc protoporphyrin-9 (10nM to microM), an inhibitor of heme oxygenase potentiated chemiluminescence of alveolar macrophages in a concentration-dependent fashion.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Monóxido de Carbono/metabolismo , Macrófagos Alveolares/metabolismo , Acridinas/farmacologia , Análise de Variância , Animais , Northern Blotting , Monóxido de Carbono/farmacologia , GMP Cíclico/metabolismo , Guanilato Ciclase/antagonistas & inibidores , Heme Oxigenase (Desciclizante)/antagonistas & inibidores , Técnicas In Vitro , Medições Luminescentes , Macrófagos Alveolares/efeitos dos fármacos , Azul de Metileno/farmacologia , Protoporfirinas/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
Aspiration pneumonia is associated with decreases in both swallowing and cough reflexes and is the most common cause of death in the elderly. Basal ganglia strokes might predispose these patients to develop pneumonia owing to reductions of both reflexes, resulting in frequent aspiration during sleep. An impairment of dopamine metabolism in the basal ganglia is observed in these patients and levodopa administration improves the impaired swallowing reflex. Both swallowing and cough reflexes are mediated by endogenous substance P (SP) released from vagal sensory nerves in the pharynx and upper airways. The addition of a low dose of capsaicin to liquid or food, which stimulates the release of SP, may help prevent aspiration pneumonia. Angiotensin-converting enzyme inhibitor decreases SP catabolism resulting in improvements in both reflexes. Oral care and the sitting position after meals may decrease aspiration pneumonia in the elderly.
Assuntos
Pneumonia Aspirativa/prevenção & controle , Pneumonia Aspirativa/fisiopatologia , Idoso , Envelhecimento/fisiologia , Gânglios da Base/fisiopatologia , Infarto Cerebral/fisiopatologia , Tosse/fisiopatologia , Deglutição/fisiologia , HumanosRESUMO
1. Although monumental efforts have been made to define the action sites of cough, the importance of neurotransmitter systems in the cough reflex has received limited attention. We studied the roles for four major neurotransmitters [acetylcholine, histamine, serotonin (5-hydroxytryptamine, 5-HT) and dopamine] in the modulation of the cough reflex. 2. Atropine (muscarinic cholinergic blocking agent), pyrilamine maleate (PM, histamine H1 blocker), cimetidine (histamine H2 blocker), 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT, specific 5-HT1A receptor agonist) and SCH-23390 (selective dopamine D1 receptor antagonist) were examined on the cough response to inhaled capsaicin in conscious guinea-pigs. 3. All the drugs significantly decreased the number of capsaicin-induced coughs in a dose-dependent manner. To compare the sensitivity of these drugs on cough response, we calculated the effective doses for 50% inhibition of cough (ED50) when the animals were exposed to 3 x 10-4 m capsaicin. The ED50 values were 0.03 microm kg-1 for atropine, 0.2 microm kg-1 for 8-OH-DPAT, 6.2 microm kg-1 for SCH-23390, 8.5 microm kg-1 for PM and 13.9 microm kg-1 for cimetidine. 4. These findings indicated that all these four neurotransmitters may be involved in the regulation of the cough reflex. Multiple changes of these neurotransmitters in disorders of the central nervous system might synergically affect the cough reflex.
Assuntos
Capsaicina/toxicidade , Sistema Nervoso Central/efeitos dos fármacos , Tosse/induzido quimicamente , Tosse/fisiopatologia , Animais , Sistema Nervoso Central/fisiologia , Tosse/tratamento farmacológico , Relação Dose-Resposta a Droga , Cobaias , Masculino , Receptores Colinérgicos/fisiologia , Receptores Dopaminérgicos/fisiologia , Receptores Histamínicos/fisiologia , Receptores de Serotonina/fisiologiaRESUMO
Histamine N-methyltransferase (HMT) expressed in the epithelial and endothelial cells of the airways is a principal enzyme degrading histamine in the body. This brief review summarizes the recent advances in molecular biology related to the pathophysiological role of HMT in regulating airway functions.
Assuntos
Brônquios/enzimologia , Histamina N-Metiltransferase/fisiologia , Traqueia/enzimologia , Animais , Clonagem Molecular , Histamina/metabolismo , Histamina N-Metiltransferase/genética , Humanos , Infecções Respiratórias/enzimologia , Viroses/enzimologiaRESUMO
The cause of the high asthma mortality in the elderly is not exactly known. We measured intrabronchial pressures in elderly asthma patients who had long-standing asthma and compared them with those in newly-diagnosed asthma and young healthy volunteers. In elderly asthmatics, at baseline conditions, both central and peripheral airway resistances were significantly higher compared with those in the other groups, which may partly explain the high asthma mortality in the elderly. We report a case of severe acute asthma associated with disturbed consciousness, in which asthma-induced cerebral swelling was considered to be accompanied by neuronal damage, after examination of cerebrospinal fluid. Inhaled steroid is essential for the treatment of moderate to severe asthma. However, approximately 40% of the elderly patients in this category did not use inhaled steroid. Physicians should strongly recommend the use of inhaled steroid to prevent asthma death in elderly asthma patients.
Assuntos
Antiasmáticos/administração & dosagem , Asma/diagnóstico , Asma/tratamento farmacológico , Beclometasona/administração & dosagem , Administração por Inalação , Idoso , Asma/psicologia , Cognição , HumanosRESUMO
Exhaled carbon monoxide (CO) concentrations were measured on a CO monitor by vital capacity maneuvers in asthmatic patients either receiving or not receiving inhaled corticosteroids, and in nonsmoking healthy control subjects. CO was detectable and measured reproducibly in the exhaled air of all subjects. The exhaled CO concentrations were higher in asthmatic patients not receiving inhaled corticosteroids and similar in asthmatic patients receiving inhaled corticosteroids and nonsmoking healthy control subjects (Am J Respir Crit Care Med 1997: 156: 1140-1143). All patients with inhaled corticosteroid treatment had reductions in exhaled CO concentration and eosinophil cell counts in sputum that were accompanied by an amelioration of airway obstruction. These results showed that detection of exhaled CO could be a simple non-invasive tool for monitoring airway inflammation and acute exacerbation of asthma.