RESUMO
The radial artery approach is becoming more popular for diagnostic cardiac catheterization and interventional procedures because of its lower incidence of access site complications and decreased patient discomfort after the procedure. However, Allen's test reveals inadequate blood supply through the ulnar artery to the hand, and therefore the approach does not seem to be suitable in 10%-30% of patients. Here we demonstrated a new percutaneous ulnar artery approach for coronary angiography in nine patients. We succeeded in obtaining an entry site into the left ulnar artery in seven patients. The average time for cannulation and that for catheterization procedure were comparable with those of the radial approach previously reported from other laboratories. Complications such as bleeding, loss of an ulnar pulse, ulnar nerve injury, and the formation of an aneurysm or fistula were not observed in any patient. The ulnar approach may be another technique that decreases patient discomfort and risk, while preserving the radial artery as a potential coronary bypass graft for surgical myocardial revascularization. Cathet Cardiovasc Intervent 2001;53:410-414.
Assuntos
Angina Pectoris/diagnóstico por imagem , Angiografia Coronária/métodos , Infarto do Miocárdio/diagnóstico por imagem , Artéria Ulnar/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Angina Pectoris/terapia , Cateterismo Cardíaco/métodos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Infarto do Miocárdio/terapiaRESUMO
Immediate early genes and heat shock protein (HSP) 70s, which may play a role in adaptation and cellular protection, respectively, are induced by ischemia in hearts. We examined if the induction of immediate early gene (c-fos, c-myc, c-jun, and junB) and HSP70 mRNAs by ischemia is affected by ischemic preconditioning. Transient ischemia (5 or 10 minute) was applied to Wistar rat (n=75) hearts, by tightening a snare placed around left coronary arterial branches 7 days before applying ischemia. Rats without earlier ischemia (control group, C) and rats with 5-minute ischemia 12 or 24 hours earlier (EI12 or 24 group) were given 10-minute ischemia and sacrificed at 0, 0.5, 1, 2, and 4 hour. RNA was extracted from the ischemic region and Northern blot analysis was performed. The induction of c-fos and c-myc mRNAs was significantly increased in EI12 but not in EI24 compared with that in C. The induction of c-jun and junB mRNAs showed no change in both EI12 and EI24 compared with that in C. The induction of HSP72 and 73 mRNAs was decreased in EI12 and decreased further in EI24. Thus, ischemic preconditioning altered the induction of immediate early gene and HSP70 mRNAs by ischemia. The effect of preconditioning differed among genes studied and changed with time after preconditioning. Ischemic preconditioning alters protective and adaptive responses to ischemia at the gene level.
Assuntos
Genes Precoces/genética , Proteínas de Choque Térmico HSP70/genética , Precondicionamento Isquêmico Miocárdico , RNA Mensageiro/metabolismo , Adaptação Fisiológica/genética , Animais , Northern Blotting , Masculino , Ratos , Ratos WistarRESUMO
OBJECTIVE: Anchoring cardiac myocytes to extracellular matrix, which is mediated mainly by integrins on their surfaces, is important for maintaining the architecture of myocardial tissues and transmitting mechanical force. We evaluated the expression of alpha integrin subunits on myocytes and the accumulation of interstitial collagen and fibronectin at acute and chronic stages after myocardial infarction. METHODS: Myocardial infarction was induced by ligation of left coronary arteries in rats. The expression of alpha 1, alpha 3 and alpha 5 integrin subunits, and accumulation of collagen and fibronectin were analyzed with immunohistochemistry or sirius-red staining. RESULTS: In hearts without infarction, moderate expression of the alpha 3 subunit and only slight expression of the alpha 5 subunit were observed on myocytes. In the first week after infarction, the alpha 1 subunit, collagen and fibronectin were increased only in the peri-infarcted area, while the alpha 5 subunit was increased both in peri-infarcted and non-infarcted areas. At day 42, the expression of the alpha 1 subunit and collagen were still increased, although the alpha 5 subunit and fibronectin were decreased. The expression of the alpha 3 subunit was not altered throughout the experimental period. CONCLUSION: These data suggest that integrin subunits play an important role in healing and remodeling processes after myocardial infarction.
Assuntos
Antígenos CD/metabolismo , Integrinas/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Animais , Antígenos CD/análise , Adesão Celular , Doença Crônica , Colágeno/análise , Colágeno/metabolismo , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Fibronectinas/análise , Fibronectinas/metabolismo , Imuno-Histoquímica , Integrina alfa1 , Integrina alfa3 , Integrina alfa5 , Integrinas/análise , Masculino , Miocárdio/química , Ratos , Ratos WistarRESUMO
Alcohol ingestion often provokes attacks in patients with vasospastic angina. Type 2 aldehyde dehydrogenase (ALDH2) deficiency, which is based on a single point mutation (Glu487Lys) of the ALDH2 gene, is common in the Japanese population, but rare among the Caucasian population. We investigated how the genotype of ALDH2 affects the characteristics of alcohol-induced vasospastic angina. Ninety-one patients with vasospastic angina who had ingested alcohol daily or occasionally were studied. Patients had been diagnosed as vasospastic angina by a provocation test with an intracoronary injection of ergonovine or acetylcholine during coronary angiography. The Glu487Lys mutation was detected by allele specific PCR. We interviewed the patients to obtain information concerning the relationship between alcohol ingestion and anginal attacks. Alcohol ingestion induced attacks in 16 of 66 patients without the Glu487Lys mutation, 8 of 22 in heterozygotes, and 1 of 3 in mutant homozygotes. The intervals between alcohol ingestion and the onset of anginal attacks were shorter in homozygotes (0.17 hours) and heterozygotes (1.5+/-0.6 hours) for ALDH2*2 than in normal homozygotes for ALDH2*1 (5.4+/-0.6 hours). The amount of ethanol which induced attacks was significantly greater in normal homozygotes than in homozygotes (11 ml) and heterozygotes (42.5+/-7.1 ml) for ALDH2*2 (96.1+/-13.4 ml in normal patients). The frequency of anginal attacks induced by alcohol ingestion did not differ between ALDH deficient and normal homozygotes. In ALDH deficient patients, however, anginal attacks were induced by a smaller amount of alcohol immediately after its ingestion. Thus, the ALDH2 genotype modifies the characteristics of the anginal attacks as a co-factor for the induction of vasospastic angina after alcohol ingestion.
Assuntos
Álcool Desidrogenase/genética , Consumo de Bebidas Alcoólicas/efeitos adversos , Aldeído Desidrogenase/genética , Angina Pectoris/genética , Vasoespasmo Coronário/induzido quimicamente , Vasoespasmo Coronário/genética , Predisposição Genética para Doença , Aldeído-Desidrogenase Mitocondrial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação PuntualRESUMO
The arterial media is composed of a heterogeneous population of smooth muscle cells (SMCs). Recently, the properties of SMCs were observed to be heterogeneous not only among individual cells but also among arteries of the same vascular bed. To test the hypothesis that a site-specific heterogeneity exists in the SMCs of human coronary arteries, we examined the expression of desmin, vimentin, calponin, and high-molecular-weight (h-) caldesmon in arteries of various sizes. Specimens of arteries were obtained at autopsy from 12 patients: 6 adults (67 +/- 4 years old); 3 younger adults (26 +/- 2 years old); and 3 neonates. The size of the arteries was estimated by the number of SMC layers of the media. The expression was compared in SMCs of large arteries (>10 layers in adults, >5 layers in neonates), medium-sized arteries (5-10 layers in adults, 3-5 SMC layers in neonates), and small arteries (<3 layers). In adults, the percentage of arteries positive for desmin was lower in the small (17% +/- 3%) and medium-sized arteries (44% +/- 12%) than in the large arteries (94% +/- 6%) (P < 0.01). The percentage of arteries positive for calponin was also lower in the small (18% +/- 2%) and medium-sized arteries (66% +/- 5%) than in the large arteries (100%) (P < 0.01). The percentage for vimentin and h-caldesmon did not differ among large, medium-sized, and small arteries. These observations in adults were similar to those in younger adults or neonates. The phenotypes of medial SMCs are vessel size-dependent in human coronary arteries. This finding should be important for understanding the site-specific characteristics of vascular function in the regulation of myocardial perfusion or those of vascular responses to environmental changes.
Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Vasos Coronários/metabolismo , Proteínas de Filamentos Intermediários/metabolismo , Proteínas dos Microfilamentos/metabolismo , Músculo Liso Vascular/metabolismo , Adulto , Idoso , Envelhecimento/fisiologia , Anticorpos Monoclonais , Biomarcadores , Cadáver , Proteínas de Ligação ao Cálcio/imunologia , Proteínas de Ligação a Calmodulina/imunologia , Circulação Coronária/fisiologia , Vasos Coronários/ultraestrutura , Desmina/imunologia , Desmina/metabolismo , Feminino , Imunofluorescência , Humanos , Recém-Nascido , Proteínas de Filamentos Intermediários/imunologia , Masculino , Proteínas dos Microfilamentos/imunologia , Músculo Liso Vascular/ultraestrutura , Fenótipo , Vimentina/imunologia , Vimentina/metabolismo , CalponinasAssuntos
Senescência Celular/fisiologia , Estresse Fisiológico/fisiopatologia , Cálcio/metabolismo , Divisão Celular/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Proteínas de Choque Térmico/genética , Humanos , Isquemia/fisiopatologia , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas/genética , Termodinâmica , Fatores de Transcrição/genética , Ubiquitinas/metabolismoRESUMO
Vascular lesion formations in such disease states as hypertension and atherosclerosis occur in a district-specific manner. Large conduit and small resistance arteries play district-specific roles in the regulation of organ perfusion. Using a culture method, we studied the morphology and growth of smooth muscle cells derived from small arteries (S-SMCs, less than 90 microm in internal diameter) and from larger arteries (L-SMCs, ranging from 800 to 900 microm) of the rat mesenteric arterial bed. S-SMCs showed a hill-and-valley pattern, whereas L-SMCs showed sheet or whorl formation. The majority of S-SMCs were smaller, bipolar-shaped; in contrast, the majority of L-SMCs were larger, polygonal-shaped. Actin fibers within S-SMCs were oriented in a bipolar manner from the nuclei, whereas those within L-SMCs had a radial appearance. [3H]Thymidine incorporation induced by serum, platelet-derived growth factor-AB (PDGF), or mechanical stretch was greater in S- vs L-SMCs. The population doubling time measured after the addition of serum or PDGF was shorter in S- vs L-SMCs. Thus, distinct morphological and growth phenotypes of SMCs exist in small and larger arteries of the same vascular bed.
Assuntos
Artérias Mesentéricas/citologia , Músculo Liso Vascular/citologia , Actinas/metabolismo , Animais , Divisão Celular , Células Cultivadas , Citoesqueleto/ultraestrutura , DNA/biossíntese , Desmina/metabolismo , Imuno-Histoquímica , Masculino , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Fenótipo , Fator de Crescimento Derivado de Plaquetas/farmacologia , Ratos , Timidina/metabolismoRESUMO
Genetically hypertensive animals are characterized by greater thermosensitivity and overexpression of heat shock proteins (HSP) upon thermal stimulation. We examined HSP72 expression under conditions of brief coronary occlusion or thermal stimulation, and the effects of the severity of these stimuli and of myocardial hypertrophy on the expression in hearts of spontaneously hypertensive rat (SHR) and Wistar Kyoto rat (WKY) groups, A snare was created around the left coronary artery in the SHR (n = 16) and WKY (n = 19) groups. In 7 WKY rats, the ascending aorta was banded and a snare was created simultaneously (WKY-AoB). By tying the snare, 4 weeks later, we applied 5- or 10-min coronary occlusion without opening the chest. For thermal stimulation, the SHR (n = 13) and WKY (n = 11) rats were placed in a 42 degrees C chamber for 15 or 40 min. The mRNA or protein level was estimated 1 or 24h after stimulation. In the SHR vs WKY groups, the mRNA and protein levels were higher after 5-min occlusion or 15-min thermal stimulation. After 10-min occlusion or 40-min thermal stimulation the difference was no longer observed. The overexpression was not observed in the WKY-AoB group despite the presence of hypertrophy similar to that seen in the SHR group (3.11+/-0.11 vs 3.20+/-0.06 mg/g in left ventricular weight/body weight). The HSP72 was overexpressed in hearts of genetically hypertensive animals after brief ischemia. Differential expression between the two groups was observed after mild stimuli, but not after more severe stimuli. Cardiac hypertrophy was not a major factor for determining the overexpression of HSP72.
Assuntos
Cardiomegalia/metabolismo , Miocárdio/metabolismo , Animais , Northern Blotting , Proteínas de Choque Térmico HSP72 , Proteínas de Choque Térmico/metabolismo , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKYRESUMO
The incidence of pulmonary thromboembolism (PTE) is lower in Japanese than in Caucasians. The basis for the different incidence has not been clarified. A poor anticoagulant response to activated protein C based on a single point mutation of the factor V gene (Arg506Gln) was found to be a pathogenetic factor for venous thrombosis and PTE in North America and Europe. We investigated whether the Arg506Gln mutation of factor V is responsible for the occurrence of PTE among Japanese. We analyzed genomic DNA prepared from fresh peripheral blood of 25 patients with PTE of unknown etiology (12 of acute type and 13 of chronic type) and that of 110 controls without respiratory or circulatory disorders. To detect the Arg506Gln mutation, 267 bp DNA fragments of the factor V gene including the Arg506Gln region were amplified by PCR, digested by MnlI and electrophoresed. After digestion of PCR products with MnlI, DNA fragments of 163 bp length, but not DNA fragments of 200 bp length, were identified in all samples, indicating the absence of the Arg506Gln mutation in the patients with PTE and control subjects. These results suggest that the Arg506Gln mutation is absent or very rare and not an important pathogenetic factor for PTE in Japanese.
Assuntos
Povo Asiático/genética , Fator V/genética , Mutação Puntual , Embolia Pulmonar/genética , Idoso , Arginina , Feminino , Glutamina , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Embolia Pulmonar/etnologia , Estudos SoroepidemiológicosRESUMO
Hearts hypertrophied by pressure-overload are more susceptible to ischemia than nonhypertrophied hearts, which may result from the attenuation of self-protective responses. Because heat shock proteins (HSPs) are reported to protect against ischemic injuries, we hypothesized that HSP expression by coronary occlusion may be attenuated in hypertrophied hearts. We banded the ascending aorta to develop ventricular hypertrophy and put a snare around the left coronary artery in rats. After 4 wk, coronary occlusion was applied by tightening the snare for 5 or 10 min in rats with and without aortic banding. The hearts were excised 0, 0.5, 1, 2, 4, 8, 12, and 24 h after coronary occlusion. Ischemic and nonischemic myocardial tissues were obtained after the snare was tightly tied, and dye was infused from the aorta. The mRNAs and protein of 72-kDa HSP (HSP 72) and/or 73-kDa HSP (HSP 73) were detected by Northern and Western blot analyses. Protein and mRNA levels of HSPs expressed by 5-min coronary occlusion in hypertrophied hearts (left ventricular weight, 577 +/- 16 mg) were lower compared with those in control hearts (462 +/- 9 mg). A longer period of coronary occlusion (10 min) elevated the attenuated expression to a level similar to that in control hearts. Treatment with an angiotensin-converting enzyme (ACE) inhibitor (cilazapril, 10-15 mg.kg(-1).day(-1)) for 4 wk preserved HSP mRNA expression even in hearts with ascending aortic banding. In hypertrophied hearts, HSP 72 and 73 expression by coronary occlusion was attenuated and was modulated by the duration of coronary occlusion and by ACE inhibitor treatment.
Assuntos
Cardiomegalia/metabolismo , Proteínas de Transporte/metabolismo , Doença das Coronárias/metabolismo , Proteínas de Choque Térmico HSP70 , Proteínas de Choque Térmico/metabolismo , Miocárdio/metabolismo , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Animais , Peso Corporal , Cardiomegalia/patologia , Proteínas de Transporte/genética , Cilazapril/farmacologia , Doença das Coronárias/patologia , Proteínas de Choque Térmico HSC70 , Proteínas de Choque Térmico HSP72 , Proteínas de Choque Térmico/genética , Masculino , Miocárdio/patologia , Tamanho do Órgão , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Bronchial asthma is characterized by eosinophil infiltration and tissue remodeling. Matrix metalloproteinases (MMPs) are thought to play critical roles by degradating interstitial matrices in a wide range of lung diseases associated with reorganization of the airway architecture. To investigate whether MMPs are involved in the pathologic processes of bronchial asthma, we examined MMP expression in asthmatic subjects. In situ hybridization revealed abundant expression of MMP-9 (gelatinase B) mRNA in biopsy specimens from asthmatic subjects (n = 5), with an average positive cell distribution of 117.8 +/- 41.1 (mean +/- SEM)/mm2. In contrast, sparse expression of the mRNA (10.8 +/- 4.8 /mm2) was observed in specimens from normal subjects (n = 4). The vast majority of cells expressing the mRNA were eosinophils in asthmatic tissues (92.2 +/- 1.2%). MMP-9 protein, which was confined to the submucosal cells in the normal subjects, was not abundantly expressed in inflammatory cells, but there was positive reactivity for MMP-9 protein in the extracellular matrix. Immunoelectron microscopic analysis showed sparse immunolocalization of MMP-9 in the perinuclear spaces of eosinophils, but not in the granules. These findings suggest the overexpression of MMP-9 by eosinophils in bronchial tissues of asthmatic individuals, and the participation of MMPs in the pathologic changes in asthmatic airways.
Assuntos
Asma/enzimologia , Colagenases/análise , Eosinófilos/enzimologia , Adulto , Asma/imunologia , Brônquios/enzimologia , Brônquios/imunologia , Colagenases/genética , Matriz Extracelular/química , Feminino , Expressão Gênica , Humanos , Macrófagos/enzimologia , Masculino , Metaloproteinase 9 da Matriz , RNA Mensageiro/análiseRESUMO
To test the hypothesis that anti-atherogenicity in women exerts beneficial effects to prevent restenosis formation after coronary angioplasty, we studied 493 men (988 lesions) and 81 women (159 lesions), aged 40-60 years, who had undergone successful balloon angioplasty and had follow-up angiography, 4.9 +/- 4.1 months later. We compared the extent of restenosis between men and women, and between pre- and post-menopausal women, which was assessed by a categorical definition of restenosis (more than 50% diameter stenosis at follow-up) and by percent diameter measured immediately after angioplasty and at follow-up. Hypertension was more frequent in women and a significantly lower percentage of women smoked. In women, the levels of total cholesterol and low-density lipoprotein cholesterol were higher. The location of dilated lesions, frequency of angioplasty for lesions with chronic total occlusion, and frequency of emergency angioplasty in patients with unstable angina or acute myocardial infarction were similar in men and women. Restenosis formation, estimated by the categorical definition or percent diameter, did not differ between men and women, or between pre- and post-menopausal women. Menopausal status or sex was not an independent predictor of restenosis by multivariate analysis. Thus, the benefit of anti-atherogenicity in women does not play an important role in preventing restenosis after coronary angioplasty.
Assuntos
Angioplastia Coronária com Balão , Doença das Coronárias/terapia , Adulto , Fatores Etários , Constrição Patológica , Doença das Coronárias/sangue , Vasos Coronários/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos RetrospectivosRESUMO
Although asthmatic children are often sensitized to the house-dust mite (HDM) during early childhood, it is not clear what antigenic components are associated with the early immune response of these children. To investigate this problem, we evaluated IgE, IgG, and IgG4 antibody responses to Dermatophagoides farinae (Df) by immunoblotting among three groups of children: group I aged 0-4 years, group II aged 5-9 years, and group III aged 10-14 years. In the group I subjects, positive IgE-binding reactions to 15- and 25-kDa components were found in 76% and 44% of sera, respectively. Those to other components were generally low in frequency. In contrast, positive IgG-binding reactions to 15- and 25-kDa components were found in 44% and 24% of sera, and those to 30- and 110-kDa components in 48% and 88% of sera, respectively. Positive IgG4 reactions to 15- and 25-kDa components were found in 48% and 24%, respectively, and those to other components were very low. Positive IgE-binding reactions to these components gradually became more frequent with increasing age in groups II and III, while IgG and IgG4 reactivities were not markedly different in these age groups. These results suggest that the 15- and 25-kDa proteins of Df are important antigens associated with the initial IgE response to HDM in early childhood, while the 30- and 110-kDa proteins are associated with IgG and 15-kDa components with IgG4.
Assuntos
Alérgenos/imunologia , Glicoproteínas/imunologia , Imunoglobulina E/biossíntese , Imunoglobulina G/biossíntese , Ácaros/imunologia , Adolescente , Animais , Antígenos de Dermatophagoides , Sítios de Ligação de Anticorpos , Criança , Pré-Escolar , Humanos , Immunoblotting , Lactente , Recém-NascidoRESUMO
A large volume of liquid nitrogen, (120-150 L) was applied to the houses of 4 asthmatic patients, and the mite densities of the floor dust from these houses were monitored every 2 wk for 4 mo from July to November 1989. The 1st liquid nitrogen treatment was applied in early August and decreased the mite densities to 20-44% of the pretreatment level in all cases, but they returned to the pretreatment level 3-4 wk later (on 3 occasions). The 2nd liquid nitrogen treatment was applied in early September and decreased the mite densities to 6-27% of the pretreatment level within 3 wk in all cases. However, mite numbers again increased to the pretreatment level 4 wk after treatment. The 3rd treatment was applied in mid-October and reduced the mite densities to < 6% of the pretreatment level within 2 wk, and mite numbers remained low thereafter. The results suggested that using liquid nitrogen to freeze houses reduces mite numbers, but that mite recolonization of the houses is an important problem.
Assuntos
Ácaros , Nitrogênio , Controle de Ácaros e Carrapatos , Animais , Densidade DemográficaRESUMO
This review focusses on the following issues: how the mammalian heart grows and ages; age-related changes in the mammalian heart before and after imposition of hemodynamic stress; and antiaging modulation in the mammalian heart. The heart and other organs grow and age together in the whole body, and interactions occur between these organs. Therefore, the age-related changes at the molecular and cellular level in the in vivo heart are the summation of the changes of the heart per se and the effects of other organs or tissues on the heart. Furthermore, myocytes grow and age under the influence of age-related changes in other myocytes and other types of cells in the myocardial tissue through autocrine or paracrine mechanisms, because myocytes are exposed to many biologically active substances which are released from those cells. Since hypertension and ischemia are very common hemodynamic events in aged hearts, the characteristics in aged hearts are discussed in terms of responses to hypertension or ischemia. The induction of proto-oncogenes and heat shock protein genes in response to milder hemodynamic stress such as pressure-overload and ischemia is diminished in aged hearts. However, the aged heart can respond to more severe stress to a level similar to that of young-adult hearts. Therefore, the senescent heart is characterized by its attenuated adaptation to hemodynamic stress and by its ability to adapt to limited environmental changes. Several interventions have antiaging effects on the heart at the molecular and cellular level.
Assuntos
Envelhecimento/fisiologia , Coração/fisiopatologia , Estresse Fisiológico/fisiopatologia , AnimaisRESUMO
OBJECTIVES: This study sought to investigate the effect of coronary angioplasty on chronic hypoperfusion-induced endothelial dysfunction in patients with coronary heart disease. BACKGROUND: The endothelium is an important component for organ flow regulation. Ischemia with or without reperfusion is known to cause endothelial dysfunction. We tested the hypothesis that chronic hypoperfusion impairs endothelial function in the angiographically normal coronary artery segment distal to stenosis and that the impairment by chronic hypoperfusion is reduced by coronary angioplasty. METHODS: In 13 patients with stable angina pectoris, substance P (10, 30 and 100 pmol) and nitroglycerin (200 micrograms) were sequentially infused into the coronary artery in a cumulative manner on the day after coronary angioplasty. In 10 of these patients, vascular responses to these agents were again investigated 3 months after angioplasty. Changes in vascular diameter were evaluated in vessels located proximal and distal to the target lesion, both of which were angiographically normal, by performing computer-assisted quantitative coronary angiography. In five patients, the transstenotic pressure gradient was also measured with a pressure sensor-mounted guide wire before angioplasty. RESULTS: On the day after angioplasty, the magnitude of dilation by substance P in distal segments was significantly less than that in proximal segments and inversely correlated with the transstenotic pressure gradient (p < 0.05) and lesion stenosis (p < 0.05). There was no difference in nitroglycerin-induced vasodilation between the two vessel segment groups. Three months later, the impaired response to substance P in the distal segment was restored to normal. CONCLUSIONS: We conclude that chronic hypoperfusion impairs endothelium-dependent dilation of coronary artery distal to critical stenosis in patients with ischemic heart disease and that coronary angioplasty ameliorates the endothelial dysfunction within 3 months.
Assuntos
Angina Pectoris/fisiopatologia , Angina Pectoris/terapia , Angioplastia Coronária com Balão , Endotélio Vascular/fisiopatologia , Idoso , Angina Pectoris/diagnóstico por imagem , Angiografia Coronária , Vasos Coronários/efeitos dos fármacos , Relação Dose-Resposta a Droga , Seguimentos , Humanos , Injeções Intra-Arteriais , Masculino , Pessoa de Meia-Idade , Nitroglicerina/administração & dosagem , Variações Dependentes do Observador , Estudos Prospectivos , Análise de Regressão , Fatores de Risco , Volume Sistólico/fisiologia , Substância P/administração & dosagem , Vasodilatadores/administração & dosagemRESUMO
Vulnerability of aged hearts to ischemia may be due to defects in protective mechanisms provided by heat shock proteins (HSPs). To determine whether there is a defect in the induction of HSPs by ischemia in old hearts, HSP72 and HSP73 (inducible and constitutive HSP70, respectively) mRNA induction was examined in young (2-mo-old; n = 36) and old (18-mo-old; n = 32) rat hearts. Transient (10- or 20-min) ischemia was applied by tightening a snare placed around left coronary arterial branches 3 days before examination to avoid the effect of operation on induction. HSP72 mRNA was induced markedly in young hearts after 10-min ischemia, peaked at 2 h, but was induced only slightly in old hearts. HSP73 mRNA was also induced in young hearts, peaked at 4 h, but was not induced in old hearts. The mRNAs were markedly induced in old hearts as well after 20-min ischemia, which was accompanied by the induction of HSP72 protein. Thus the age-related modulation of HSP72 and HSP73 mRNAs suggests a defective sensing mechanism for ischemia in old hearts.
Assuntos
Expressão Gênica , Proteínas de Choque Térmico HSP70/biossíntese , Isquemia Miocárdica/metabolismo , Miocárdio/metabolismo , RNA Mensageiro/biossíntese , Envelhecimento/metabolismo , Animais , Northern Blotting , Coração/crescimento & desenvolvimento , Masculino , Isquemia Miocárdica/patologia , Isquemia Miocárdica/fisiopatologia , Miocárdio/patologia , Ratos , Ratos Wistar , Valores de Referência , Fatores de TempoRESUMO
Heart disease in older individuals can be characterised as the result of 2 processes, hypertension and atherosclerosis, which are the major causes of heart failure in the elderly population. The aging heart undergoes changes at the molecular, cellular and organ levels. These age-related changes may then be modulated by pathological conditions, such as hypertension, and by the reduction of blood pressure. One characteristic of the aged heart is a limited capacity for adaptation, by hypertrophy, to increased mechanical load. This age-related attenuation of the hypertrophic response may be attributed to the diminished induction of proto-oncogenes such as c-fos, c-myc and c-jun. This diminution results from aging of the heart per se and may be modulated by extracardiac factors. With regard to the coronary vasculature, the age at which hypertension develops seems to be an important factor for determining the vascularity of hypertrophied hearts. Late-onset hypertension is not accompanied by coronary angiogenesis, and it decreases dilator reserve in spite of the absence of myocardial hypertrophy. In contrast, mechanical overload in infant hearts is accompanied by angiogenesis and normal dilator reserve. In principle, the normalisation of hypertension results in the regression of myocardial hypertrophy and decreased coronary dilator reserve. In aged hearts, it is not clear how hypertension-induced myocardial hypertrophy or coronary vascular changes regress. Although antihypertensive treatment is clearly associated with an improvement of cardiovascular mortality and morbidity in hypertensive elderly individuals, it remains unclear how treatments ameliorate the hypertension-induced alterations.
Assuntos
Envelhecimento , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Cardiomegalia , Colágeno/metabolismo , Doença das Coronárias/fisiopatologia , Exercício Físico , Coração/fisiologia , Coração/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Hipertensão/fisiopatologia , Miocárdio/metabolismo , Miocárdio/patologiaRESUMO
In aged individuals the incidence of heart failure is higher than in younger subjects. Ischemic events are also common in the aged heart because of changes in the coronary vasculature and myocytes caused by aging. Adaptational responses to increased hemodynamic overload and to ischemia in the aged heart are discussed at the molecular, cellular and organ levels. One characteristic of the aged heart is a limited capacity for adaptation with hypertrophy to increased mechanical load. This age-related attenuation of the hypertrophic response may be attributed to the diminished induction of proto-oncogenes such as c-fos, c-myc and c-jun by hemodynamic stress. This diminution results from the aging of the heart per se and may be modulated by extracardiac factors. An age-related diminution was also observed in the mRNA induction of heat shock proteins by transient ischemia. However, this diminished induction of immediate early genes in the aged heart was not observed after more severe stress. With regard to the coronary vasculature, the age at which pressure-overload begins seems to be one of the important factors which determine the vascularity of hypertrophied hearts. Late-onset pressure-overload decreased dilator reserve in spite of the absence of myocardial hypertrophy. Thus, the responses to stress in the aged heart are quite different from those in the young heart. The limited capacity for adaptation to hemodynamic overload and poor protective mechanisms against stress may be causes of the higher incidence of heart failure in the aged.