Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Endocr Regul ; 47(1): 33-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23363255

RESUMO

OBJECTIVE: This work was aimed to evaluate the prevalence of insulin resistance (IR) and metabolic syndrome in a large cohort of 40-60 years old patients with cardiovascular symptoms. METHODS: A total of 500 consecutive males and females referred to coronarography and coronary catheterization, because of spontaneous or after load precordial pain plus denivelisation of ST segment by electrocardiography, were included. Besides standard clinical examinations, ergometry, echocardiography, fundamental laboratory tests, and several other laboratory examinations were also performed, including oral glucose toleration test (OGTT), total and high-density lipoprotein (HDL) cholesterol, triglycerides, apoprotein A1 and B, apolipoprotein (a), uric acid, fibrinogen, plasminogen activator inhibitor-1 (PAI-1), cytokines (tumor necrosis factor α, TNFα, interleukin-1, IL-1, interleukin-6, IL-6), endothelin-1, as well as hormones (insulin, C peptide, leptin, growth hormone, cortisol). RESULTS: In 81.6% of patients, IR syndrome with compensatory hyperinsulinemia was found in a positive correlation with various symptoms of metabolic syndrome, including abdominal obesity, increased body mass index (BMI), dysglycemia, dyslipoproteinemia, coronary stenosis, decreased HDL level, and hypertension. Hirsutism with polycystic ovarian syndrome was found in 52% of examined women with IR. However, a normal coronary angiogram, called as a microvascular form of the angina pectoris (MIV-AP), was found in 14% of predominantly periclimacteric and benign hirsutic females with long-term disorders of menstrual cycle. Since these patients showed the same symptoms as their gender, age, BMI, and degree of coronary stenoses adjusted pairs with the macrovascular form (such as the same levels of several lipids, hormones and obesity measures), our data strongly support the view that MIV-AP might belong to the IR syndrome. CONCLUSIONS: Hyperinsulinemia and high prevalence of various symptoms of metabolic syndrome (MS) were found in high percentage of patients with after load precordial pain who were referred to coronarography. Similarly, in several women, MIV-AP was detected and its affiliation to MS suggested.


Assuntos
Angiografia Coronária , Resistência à Insulina , Síndrome Metabólica/diagnóstico por imagem , Síndrome Metabólica/epidemiologia , Angina Microvascular/diagnóstico por imagem , Angina Microvascular/epidemiologia , Adulto , Angina Pectoris/complicações , Angina Pectoris/diagnóstico por imagem , Angina Pectoris/epidemiologia , Estudos de Coortes , Angiografia Coronária/estatística & dados numéricos , Feminino , Humanos , Resistência à Insulina/fisiologia , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/metabolismo , Angina Microvascular/complicações , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/diagnóstico por imagem , Obesidade/epidemiologia , Sobrepeso/complicações , Sobrepeso/diagnóstico por imagem , Sobrepeso/epidemiologia , Prevalência , Encaminhamento e Consulta/estatística & dados numéricos , Eslováquia/epidemiologia
2.
Hypertension ; 35(3): 740-5, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10720588

RESUMO

In the present study, we assessed whether activation of the nitric oxide (NO) system within the renal medulla could serve as a buffer against the chronic hypertensive effects of arginine vasopressin (AVP). NO concentration in the renal medulla of Sprague-Dawley rats was measured with in vivo microdialysis/oxyhemoglobin NO trapping. The results showed that medullary interstitial [NO] was increased after 2 hours of AVP infusion and remained elevated even after 10 days (by 62+/-8% and 42+/-13%, respectively). Western blot analysis showed that 2 days of AVP infusion was insufficient to increase protein expression of any of the NO synthase (NOS) isoforms, but after 10 days of AVP infusion, endothelial NOS expression was significantly increased in the inner medulla with no significant changes in noninducible NOS and inducible NOS levels. When renal medullary NOS enzyme activity was blunted with a nonpressor dose of N(G)-nitro-L-arginine methyl ester (75 microg. kg(-1). h(-1)) that was chronically infused locally into the renal medulla, intravenous AVP infusion (which was shown earlier to be subpressor in chronic studies) produced a sustained elevation in arterial pressure (from 107+/-2 to 121+/-2 mm Hg). These data indicate that chronic elevations in plasma AVP enhance renal medullary endothelial NOS protein expression, which enables sustained elevations of NO concentrations in this region of the kidney to buffer the hypertensive effects of AVP.


Assuntos
Arginina Vasopressina/farmacologia , Hipertensão Renal/metabolismo , Medula Renal/enzimologia , Óxido Nítrico/metabolismo , Fármacos Renais/farmacologia , Animais , Arginina/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Endotélio Vascular/enzimologia , Inibidores Enzimáticos/farmacologia , Hipertensão Renal/induzido quimicamente , Infusões Intravenosas , Medula Renal/irrigação sanguínea , Medula Renal/efeitos dos fármacos , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo III , Ratos , Ratos Sprague-Dawley , Circulação Renal/efeitos dos fármacos , Circulação Renal/fisiologia
3.
Maturitas ; 34(1): 83-92, 2000 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-10687886

RESUMO

OBJECTIVES: The purpose of this study was to determine the effects of long-term combined sexual hormone replacement therapy on the biomechanical properties of the small artery wall in castrated female rats. METHODS: 30 non-pregnant mature female Sprague-Dawley rats were pharmacologically ovariectomized with 750 microg/kg triptorelin im. every 4th week. Ten of them received combined hormone replacement in form of 15 mg/kg medroxyprogesterone acetate (MPA) im. every 2 weeks and 450 microg/kg estradiol propionate im. once a week. Ten castrated animals received MPA only. Ten control, castrated animals were given the vehicles of these steroids. Ten other animals were kept parallelly, receiving the vehicles of all drugs (control animals). After 12 weeks of treatment cylindrical segments of the saphenous artery were isolated and cannulated at both ends and subjected to in vitro microarteriographic test. Pressure diameter curves, in the range of 0-200 mmHg, were recorded from segments in normal Krebs-Ringer (nKR) solution, in contraction with norepinephrine (1.6 x 10(-5) M), and then in relaxation with papaverine (2.8 x 10(-5) M). Biomechanical parameters were calculated based on the pressure diameter curves. RESULTS: Combined hormone replacement therapy significantly increased the passive diameter of small arteries, as compared to those from ovariectomized animals without hormone replacement. MPA monotherapy did not alter the vessel diameter, the inner radii at 100 mmHg intraluminal pressure were, 300+/-9 microm in the control castrated, 340+/-7 microm in the estradiol + MPA replaced and 306+/-8 microm in the MPA treated groups (P < 0.05 between the control castrated and the combined treatment groups). The vascular reactivity to norepinephrine or papaverine was not changed significantly either by combined hormone replacement or by MPA monotherapy when compared with ovariectomized controls. No significant alterations were found in wall thickness and distensibility. CONCLUSIONS: These results suggest that chronic medroxyprogesterone pretreatment does not influence the geometric, elastic and contractile properties of small arteries in castrated female rats. The combination of MPA + estradiol increased the morphological lumen: the morphological vasodilatation induced by estrogen, described earlier, was not affected by the addition of this progestin to the regimen.


Assuntos
Artérias/efeitos dos fármacos , Terapia de Reposição Hormonal , Pós-Menopausa , Resistência Vascular/efeitos dos fármacos , Animais , Artérias/fisiologia , Fenômenos Biomecânicos , Modelos Animais de Doenças , Estradiol/farmacologia , Feminino , Luteolíticos , Acetato de Medroxiprogesterona/farmacologia , Ovariectomia , Pós-Menopausa/efeitos dos fármacos , Pós-Menopausa/fisiologia , Ratos , Ratos Sprague-Dawley , Pamoato de Triptorrelina
4.
Hypertension ; 35(1 Pt 2): 418-23, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10642335

RESUMO

Studies were performed in conscious Sprague-Dawley rats to determine the role of the alpha(2)-adrenergic receptor-mediated increase in the renal medullary nitric oxide synthase (NOS) activity as a counterregulatory mechanism of blood pressure control in response to increased renal adrenergic stimulation. A subpressor dose of norepinephrine (NE, 8 microg. kg(-1). h(-1)) was infused intravenously, and NOS activity was determined with arginine-citrulline conversion by high-performance liquid chromatography in renal cortical and outer and inner medullary tissues. It was found that after 7 days of intravenous NE infusion, NOS activity was significantly higher in both the outer and inner medullary tissues (158+/-45 versus 30+/-24 pmol. mg(-1). h(-1) [outer medulla] and 5.1+/-0.7 versus 2.0+/-0.5 nmol. mg(-1). h(-1) [inner medulla] for NE-treated versus control rats, respectively). To determine whether the increase of NOS activity was mediated through renal medullary alpha(2)-receptors, the receptor antagonist rauwolscine (RAU, 1 microg. kg(-1). min(-1)) was infused via an implanted renal medullary interstitial catheter, and the consequences of intravenous NE administration were evaluated. NOS activity was significantly lower in the RAU-infused animals and did not increase with infusion of NE. To determine the systemic effects of the renal medullary alpha(2)-receptors, studies were performed to determine the consequences of chronic intravenous infusion of subpressor amounts of NE in the presence and absence of renal medullary alpha(2)-receptor inhibition. Under conditions in which RAU was continuously infused into the renal medulla, the same subpressor dose of NE caused sustained and reversible hypertension (mean arterial pressure increased from 120+/-3 to 131+/-3 mm Hg). Chronic blunting of the renal medullary NOS activity with N(G)-nitro-L-arginine methyl ester (75 microg. kg(-1). h(-1)) also enabled NE to produce a significant rise in mean arterial pressure (from 117+/-2 to 134+/-4 mm Hg). We conclude that the hypertensive effects of moderate elevations of renal adrenergic activity were chronically buffered by the alpha(2)-receptor-mediated increase in NOS activity within the renal medulla.


Assuntos
Hipertensão/enzimologia , Medula Renal/enzimologia , Óxido Nítrico Sintase/metabolismo , Norepinefrina , Simpatomiméticos , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Aorta , Arginina , Pressão Sanguínea/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Citrulina , Estado de Consciência , Ativação Enzimática/efeitos dos fármacos , Hipertensão/induzido quimicamente , Infusões Intravenosas , Córtex Renal/química , Córtex Renal/enzimologia , Medula Renal/química , Masculino , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos alfa 2/fisiologia , Ioimbina/farmacologia
5.
Vnitr Lek ; 46(4): 205-12, 2000 Apr.
Artigo em Eslovaco | MEDLINE | ID: mdl-11227172

RESUMO

Insulin resistance syndrom (IR) is often associated with the syndrome of microvascular angina pectoris (MVAP) or with coronary artery disease (CAD). The authors quantified distribution and washout of 201Tl in heart (C), lungs (L) and liver (H) to evaluate the results 201Tl stress (s) and redistribution SPECT in 50 patients. They compared 2 groups of patients with laboratory verified IR (MVAP and CAD) and control group (CG) of patients with normal coronarography without any symptoms of IR. In Patients with IR and MVAP were found significantly more frequent local perfusion abnormalities then in CG. The index sL/C calculated by ROI analysis is significantly lower in controls, then in CAD. The index sC/H is lower in patients with IR (MVAP significantly) then in CG. The washout of 201Tl in CAD myocardium decreased and in MVAP liver increased. 201thalium scintigraphy is useful for separation of patients with MVAP and local perfusion abnormalities. This findings had probably prognostic value in patients with IR.


Assuntos
Circulação Coronária , Angina Microvascular/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Doença das Coronárias/diagnóstico por imagem , Teste de Esforço , Feminino , Coração/diagnóstico por imagem , Humanos , Masculino , Angina Microvascular/fisiopatologia , Pessoa de Meia-Idade
6.
Vnitr Lek ; 45(1): 11-6, 1999 Jan.
Artigo em Eslovaco | MEDLINE | ID: mdl-10422520

RESUMO

TNF-alpha (so-called cachectin), IL-1 and 6 are important regulating agents in the homeostasis of energy in the organism, as among others they control processes of apoptosis and thus also the volume of adipose and muscular tissues. They are produced not only in immunocompetent cells but also in adipocytes and muscle cells. The cytokine system is then activated not only in tumours and infections but elevated values were found also in obesity, NIDDM, in myocardial infarction and in advanced decompensated cardiac patients. By acting on phosphorylation of IRS-1 and PI-3 kinase TNF-alpha promotes significantly insulin resistance, causes deterioration of diabetes, as well as elevated body temperature, sleepiness and anorexia. In a group of 65 patients, mostly with android obesity, in hyperleptinaemic and insulin resistant probands with coronarographically confirmed microvascular angina pectoris (n = 22) or IHD, mostly after a myocardial infarction (n = 43) with one or more significant stenoses on the epicardial coronary arteries in half the patients positive or elevated TNF-alpha was found and in 28% also IL-6. This increase did not correlate however with BMI, the percentage of body fat, IRI and C peptide levels nor with cortisol and leptin levels. Insulin resistant subjects had more frequently elevated homocysteine and Lp(a) values which are further two independent risk factors of atherothrombogenesis. Hyperhomocysteinaemia can be favourably influenced by vitamin fortification of the diet or by administration of folate and pyridoxine (1 tablet per day) involving negligible financial costs.


Assuntos
Homocisteína/sangue , Resistência à Insulina , Interleucina-1/sangue , Interleucina-6/sangue , Obesidade/sangue , Fator de Necrose Tumoral alfa/análise , Adulto , Angina Pectoris/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
Vnitr Lek ; 45(1): 22-9, 1999 Jan.
Artigo em Eslovaco | MEDLINE | ID: mdl-10422522

RESUMO

UNLABELLED: The optimal therapeutic procedure for prevention of sudden cardiac death (SCD) after myocardial infarction involves identification of the patients with a high risk of malignant ventricular arrhythmias using non-invasive risk markers, invasive electrophysiological evaluation of high risk patients, selection of treatment (ICD, RFTA, antiarrhythmics) and evaluation of the effectiveness of treatment. The objective of this work is retrospective evaluation of the incidence of risk markers of sudden cardiac death and the importance of programmed ventricular stimulation for the prognosis of patients with malignant ventricular arrhythmias after myocardial infarction. RESULTS: 1. Retrospective analysis of 87 patients with ventricular tachycardia (VT) after myocardial infarction confirmed a high incidence of non-invasive risk markers. 2. For the long-term course a combination of the left ventricular ejection fraction (LVEF) < 0.40 + reduced heart rate variability (HRV) and abnormal ventricular potentials are most important (or dispersion of QT > 80 ms). The absence of ventricular extrasystoles on the Holter monitor does not predict the course without malignant arrhythmical episodes. 3. There is a statistically significant relation to the inducibility of BP during programmed ventricular stimulation with LVEF, persisting BP, RMS voltage of the terminal 40 ms (RMS40) and QT dispersion. 4. The inducibility of BP and persistence of inducibility on antiarrhytmic drugs in patients with LVEF < 40 is associated with a 14.8% incidence of SCD within four months after the first arrhythmic episode. The authors recommend to examine LVEF as the basis of risk stratification of SCD along with values of coronary reserve after myocardial infarction. In patients with LVEF (they recommend to examine Holter s monitor (assessment of HRV and analysis of ventricular arrhythmias) and mean ECG. Abnormal late ventricular potentials, reduced HRV or BP indicate programmed ventricular stimulation.


Assuntos
Morte Súbita Cardíaca/etiologia , Infarto do Miocárdio/complicações , Taquicardia Ventricular/complicações , Adulto , Idoso , Estimulação Cardíaca Artificial , Morte Súbita Cardíaca/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Volume Sistólico , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/terapia
8.
Vnitr Lek ; 45(1): 35-9, 1999 Jan.
Artigo em Eslovaco | MEDLINE | ID: mdl-10422524

RESUMO

The cause of Afl-I is macroentry in the right atrium. The critical site of reentry is the narrow anatomical space in the isthmic region between the posterior part of the annulus of the tricuspid valve and the vena cava inferior (isthmus TA-IVC). Radiofrequency ablation (RF) of the isthmus TA-IVC is successful on average in 90% of patients. The best criterium for evaluation of short-term and long-term effect of RF ablation is a two-way block of conduction in the TA-IVC insthmus, created by RF ablation. In case of a relapse it is possible to repeat ablation. Although a proarrhythmic effect of ablation is not assumed, the cause of the higher frequency of atrial fibrillation is not known. The authors present their own experience with the treatment of Afl-I by RF ablation of the TA-IVC isthmus in a group of 18 patients. RF ablation was successful in 83.3% patients of the group, no complications were recorded. Late relapses of Afl-1 in three patients were resolved by repeated RF ablation which was successful. The results are comparable with results in other departments. Based on their own experience the authors consider ablation treatment of Afl-1 a safe and effective therapeutic method in a selected group of patients.


Assuntos
Flutter Atrial/cirurgia , Ablação por Cateter , Flutter Atrial/diagnóstico , Ablação por Cateter/métodos , Eletrocardiografia , Feminino , Humanos , Masculino , Recidiva
9.
Hypertension ; 33(1 Pt 2): 440-5, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9931144

RESUMO

We hypothesized that the relatively high doses of angiotensin (Ang) II required to produce hypertension in rats were related to stimulation of renal medullary nitric oxide production, which in turn blunted reductions in medullary blood flow and the development of hypertension. Ang II was infused (5 days at 3 ng. kg-1. min-1 IV) to uninephrectomized Sprague-Dawley rats in the presence and absence of a continuous medullary interstitial NG-nitro-L-arginine methyl ester (L-NAME) infusion. Renal cortical and medullary blood flows were determined with the use of implanted optical fibers and laser-Doppler flowmetry. Ang II in the absence of medullary nitric oxide synthase inhibition did not change cortical or medullary blood flow or mean arterial pressure. A threshold dose of L-NAME was determined (75 microg. kg-1. h-1) that did not produce significant short- or long-term changes in medullary blood flow and mean arterial pressure. In rats with blunted medullary nitric oxide synthase activity, Ang II infused intravenously resulted in a 30% reduction in medullary blood flow (from 1.3 to 0.9+/-0.2V) and approximately 20 mm Hg increase in mean arterial pressure with Ang II infusion over 5 days. During 70 minutes after the start of intravenous Ang II, there was an immediate reduction in medullary blood flow, with no changes in cortical blood flow or mean arterial pressure. We conclude that the relative insensitivity of rats to long-term elevations of circulating Ang II is due to the potent counterregulatory actions of the nitric oxide system, specifically within the renal medulla. The results provide novel insights of how the organism attempts to protect itself from the hypertensive effects of Ang II.


Assuntos
Angiotensina II/farmacologia , Hipertensão/fisiopatologia , Córtex Renal/irrigação sanguínea , Medula Renal/irrigação sanguínea , NG-Nitroarginina Metil Éster/farmacologia , Circulação Renal/efeitos dos fármacos , Angiotensina II/administração & dosagem , Animais , Pressão Sanguínea/efeitos dos fármacos , Sinergismo Farmacológico , Hipertensão/induzido quimicamente , Infusões Intravenosas , Infusões Parenterais , Córtex Renal/efeitos dos fármacos , Medula Renal/efeitos dos fármacos , NG-Nitroarginina Metil Éster/administração & dosagem , Nefrectomia , Ratos , Ratos Sprague-Dawley , Fluxo Sanguíneo Regional/efeitos dos fármacos , Circulação Renal/fisiologia , Fatores de Tempo
10.
Bratisl Lek Listy ; 100(7): 371-8, 1999 Jul.
Artigo em Eslovaco | MEDLINE | ID: mdl-10622115

RESUMO

BACKGROUND: Risk stratification of malignant ventricular tachyarrhythmias and sudden cardiac death after myocardial infarction is essentially important for high risk patients identification, who require specific therapeutic procedures. Non-invasive risk markers--LVEF, late potentials LP, Q-T dispersion, decreased heart rate variability (HRV) and baroreflex sensitivity (BRS)--and ventricular tachycardia inducibility have low positive predictive value. The appropriate combination and consecutiveness which will provide most precise identification of patients threatened by sudden arrhythmic death, applicable to all patients after myocardial infarction, is being analysed. METHODS: In a group of 87 patients after myocardial infarction suffering from ventricular tachycardia retrospective assessment of sudden cardiac death risk markers incidence was performed. RESULTS: 1. The most frequent risk marker was LVEF 0.40 (48.3%), abnormal LP (84.9%), DQT 80 ms and decreased HRV (73.1%) and their combinations. 2. Patients with inducible ventricular tachycardia (62.1%) had lower LVEF in comparison with non-inducible ventricular tachycardia patients (0.42 +/- 0.11 vs 0.51 +/- 0.01, p = 0.002), higher QT dispersion (85.0 +/- 30.5 ms versus 63.6 +/- 30.7 ms, p = 0.003). 3. In patients with recurrent malignant ventricular tachyarrhythmias and sudden cardiac death occurring during the follow-up is sustained inducible ventricular tachycardia with antiarrhythmic therapy and induction of ventricular tachycardia during native state significantly more frequent. LVEF is significantly reduced, FQRS on SAECG is significantly prolonged, DQT is significantly higher. CONCLUSION: On the basis of the results and data from literature the authors recommend LVEF assessment in all patients after myocardial infarction and further stratification in patients with left ventricular dysfunction.


Assuntos
Infarto do Miocárdio/complicações , Taquicardia Ventricular/diagnóstico , Adulto , Idoso , Morte Súbita Cardíaca , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Taquicardia Ventricular/tratamento farmacológico , Taquicardia Ventricular/etiologia
11.
Circ Res ; 81(6): 988-95, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9400379

RESUMO

In this study, we compared the level of myogenic tone and its negative-feedback control through specific K+ channels in two types of human veins (saphenous [SV] and cephalic [CV] veins), which experience different ranges of pressure in vivo. We also investigated whether an experimental model of increased venous pressure in rats exposed to head-up tilt for 2 weeks produced changes similar to those observed in the human veins. Cylindrical vein segments were cannulated, their diameters were measured, and the intraluminal pressure was set at different levels (2 to 30 mm Hg) in vitro. Acetylcholine test showed that during the regular harvesting process 76% of the human SVs exposed for coronary bypass grafts had no functional endothelium. We found significant myogenic tone in the human SV, where the in vivo pressure is high, but it was not present in the human CV, where the in vivo pressure is low. The nonspecific K+ channel antagonist, tetraethylammonium (TEA), decreased the diameter of the human SV but not the CV. Iberiotoxin and 4-aminopyridine, blockers of the Ca(2+)-sensitive (KCa) and voltage-gated K+ (KV) channels, also decreased the diameter of the human SV by 10.2 +/- 4.8% and 19.5 +/- 4.7%, respectively. In the rat SV, significant myogenic tone was found, but TEA had no effect, even after 2 weeks of in vivo pressure increase in the hindlimb by head-up tilt. We conclude that (1) an increased venous myogenic tone correlates with higher chronic intraluminal pressure loads, (2) KCa and KV channels counterregulate the myogenic tone in human, but not in rat, saphenous vein, (3) the counterregulatory effect is more effective at high than at low intraluminal in vitro pressure levels, and (4) its development is probably a long-term process.


Assuntos
Pressão Sanguínea , Músculo Liso Vascular/fisiologia , Canais de Potássio/fisiologia , Veias/fisiologia , Acetilcolina/farmacologia , Adulto , Idoso , Animais , Endotélio Vascular/fisiologia , Humanos , Pessoa de Meia-Idade , Ratos , Ratos Sprague-Dawley , Compostos de Tetraetilamônio/farmacologia
12.
Bratisl Lek Listy ; 98(7-8): 374-8, 1997.
Artigo em Eslovaco | MEDLINE | ID: mdl-9471330

RESUMO

Non-homogenity of ventricular myocardial repolarization is a substrate for the reentry mechanism of ventricular arrhythmias. It is manifestant by dispersion of Q-T and Q-Tc intervals on the standard ECG curve. The authors studied the possibility of using the dispersity of Q-T and Q-Tc intervals in clinical practice. They evaluated the dispersion of these intervals within the set of 21 patients after myocardial infarction with sustained ventricular tachycardia, and compared it with the dispersion within the control set of 17 patients after myocardial infarction without an arrhythmic episode. By means of comparison, they have discovered that: 1) the dispersion of Q-T and Q-Tc intervals is significantly higher in patients with ventricular tachycardia: Q-T (mean +/- SE) 82.8 +/- 7.8 msec vs 42.2 +/- 4.8 msec, Q-Tc 93.0 +/- 10.2 msec vs 47.1 +/- 4.8 msec, p > 0.001, 2) the dispersion of Q-Tc when higher than 60 msec is an optimum discrimination value for the prognosis of sudden arrhythmic death after myocardial infarction (sensitivity 81%, specificity 76%) and 3) the dispersion of Q-T and Q-Tc intervals has no relation to the function of the left ventricle. Therefore the authors consider the dispersion of Q-T and Q-Tc intervals as being a useful marker of malignant ventricular arrhythmia which could be included into the algorithm of assessment of the risk of sudden arrhythmic death after myocardial infarction.


Assuntos
Eletrocardiografia , Infarto do Miocárdio/fisiopatologia , Morte Súbita Cardíaca/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Prognóstico , Sensibilidade e Especificidade , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologia
13.
Pflugers Arch ; 433(4): 536-8, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9000434

RESUMO

Direct vascular effects of somatostatin (ST) were investigated in cat superior mesenteric artery (SMA) segments in vitro. Changes of outer diameter were measured at constant axial length and perfusion pressure. SMA segments in the resting state were not affected by ST, regardless of endothelial integrity. Noradrenaline-preconstricted SMA segments were dilated concentration-dependently by ST (EC50 10(-13) mol/l). At maximal dilatation (by 10(-11) mol/l ST) the preconstriction was diminished to 45 +/- 9% (P<0.001). Perfusion with Triton X-100, or NG-nitro-L-arginine nearly abolished the ST-induced dilatation, while indomethacin treatment partially suppressed it. We conclude that ST dilates preconstricted cat SMA segments mainly via the endothelial release of nitric oxide, and additionally via prostaglandins.


Assuntos
Artérias Mesentéricas/efeitos dos fármacos , Óxido Nítrico/fisiologia , Prostaglandinas/fisiologia , Somatostatina/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Gatos , Relação Dose-Resposta a Droga , Feminino , Masculino
14.
Bratisl Lek Listy ; 98(11): 609-12, 1997 Nov.
Artigo em Eslovaco | MEDLINE | ID: mdl-9525053

RESUMO

The authors present a retrospective evaluation of the risk stratification and therapy of 53 patients with ventricular tachycardia. They present the diagnostical algorithm used for the detection of risk of sudden death. The most frequently used drug in the set of patients was amiodarone in monotherapy or in combination with other drugs. Sotalol was used for both, its antiarrhythmic nature, and for its ability to reduce the defibrillation threshold in patients with an implanted automatic implantable cardiovertor-defibrillator (AICD). Antiarrhythmic drugs of class I in monotherapy were used in patients with non-coronary causes of ventricular tachycardia and with normal left ventricular function. The authors, on the basis of sudden death of three patients with low ejection fraction of the left ventricle which were recorded even despite Holter apparatus and electophysiologically confirmed supression of ventricular tachycardia, recommend to consider in this group of patients the primary AICD implantation. (Tab. 4, Fig. 2, Ref. 13.)


Assuntos
Antiarrítmicos/uso terapêutico , Taquicardia Paroxística/tratamento farmacológico , Taquicardia Ventricular/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Am J Physiol ; 271(6 Pt 2): H2238-45, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8997279

RESUMO

The vascular effects of somatostatin (ST) and its mechanism of action are not well understood. In the present study, we investigated the direct effects of ST on the vascular tone of rat saphenous artery and vein using videomicroangiometry in situ. ST was administered either in superfusion or in infusion. We found opposite effects in arteries and veins: ST (10(-12)-10(-7) M) dilated the artery (outer diameter increased from 533 +/- 28 to 600 +/- 29 microns, administered in superfusion) and contracted the vein (from 709 +/- 26 to 640 +/- 26 microns and from 775 +/- 30 to 708 +/- 60 microns in superfusion and infusion, respectively). These effects of ST were completely abolished after deendothelization (air bolus maintained for 6 min in vessel lumen) and after local infusion of NG-nitro-L-arginine (L-NNA; 10(-4) M), a nitric oxide (NO) synthesis inhibitor. An NO-dependent basal vasodilator tone in the rat saphenous vein responsible for 10.9 +/- 0.3% of the total vessel diameter was found. After ST administration the venous diameter reduction was similar to that measured after deendothelization or L-NNA. We conclude that ST in situ induces NO release from endothelial cells of rat saphenous artery causing vasodilation, whereas, in contrast, it inhibits the basal NO-dependent vasodilator tone of the saphenous vein inducing vasoconstriction.


Assuntos
Óxido Nítrico/fisiologia , Veia Safena/efeitos dos fármacos , Somatostatina/farmacologia , Coxa da Perna/irrigação sanguínea , Animais , Artérias/efeitos dos fármacos , Endotélio Vascular/fisiologia , Inibidores Enzimáticos/farmacologia , Feminino , Masculino , Óxido Nítrico/antagonistas & inibidores , Nitroarginina/farmacologia , Ratos , Ratos Sprague-Dawley , Vasoconstrição , Vasodilatação
16.
Vnitr Lek ; 42(3): 147-9, 1996 Mar.
Artigo em Eslovaco | MEDLINE | ID: mdl-8686199

RESUMO

Patients with the Romano-Ward long QT interval syndrome run a high risk of sudden cardiac death. Beta-blockers of the sympathetic nerve are effective treatment. Some patients die suddenly despite this treatment. The treatment of choice is a combination of beta-blockers of the sympathetic nerve and cardiostimulation. The authors describe a group of their own five patients from three families with the Romano-Ward syndrome. The course was favourable. The stimulation rate needed for normalization of the QT interval and a favourable clinical development was 78 +/- 6 imp./min. Based on data in the literature and their own experience the authors recommended combined treatment with beta-blockers and cardiostimulation in patients with the Romano-Ward syndrome, if monotherapy with beta-blockers is not effective.


Assuntos
Síndrome do QT Longo/terapia , Taquicardia Ventricular/prevenção & controle , Antagonistas Adrenérgicos beta/uso terapêutico , Terapia Combinada , Feminino , Humanos , Síndrome do QT Longo/complicações , Masculino , Pessoa de Meia-Idade , Marca-Passo Artificial , Taquicardia Ventricular/etiologia
17.
Physiol Res ; 45(4): 291-6, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9085352

RESUMO

The mechanisms of the vascular effects of somatostatin (ST) are not well known. This study compares the direct effect of ST in different vascular regions and species. Isolated perfused segments of the cat superior mesenteric artery in vitro did not exhibit a vascular response in the resting state, however, ST-induced vasodilatation was observed with norepinephrine preconstriction. In contrast, ST only slightly dilated superior mesenteric vein segments. In the artery, NG-nitro-L-arginine inhibited both ST and endothelium-dependent nitric oxide (NO) mediated response. No regular dose-response curves were found when ST was applied on the large mesenteric artery in the cat, but rings of small mesenteric artery from both cats and dogs exhibited dose-dependent relaxations. These effects were also NO-dependent. Local application of ST on the rat saphenous artery in situ elicited NO-mediated dose-dependent vasodilatation. However, ST constricted rat saphenous veins in the case of either adventitial or intraluminal application. It is concluded that ST exerts different actions on the arterial and the venous vessel wall. The major response in arteries is endothelium-mediated vasodilatation seen in various species and vascular beds. Large and small arteries respond differently to ST but these differences require further elucidation.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Óxido Nítrico/fisiologia , Somatostatina/farmacologia , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Acetilcolina/farmacologia , Animais , Gatos , Cães , Relação Dose-Resposta a Droga , Endotélio Vascular/química , Endotélio Vascular/fisiologia , Inibidores Enzimáticos/farmacologia , Artérias Mesentéricas/efeitos dos fármacos , Artérias Mesentéricas/fisiologia , NG-Nitroarginina Metil Éster/farmacologia , Norepinefrina/farmacologia , Ratos , Veia Safena/efeitos dos fármacos , Veia Safena/fisiologia , Vasoconstritores/farmacologia
18.
Vnitr Lek ; 41(2): 121-5, 1995 Feb.
Artigo em Eslovaco | MEDLINE | ID: mdl-7725636

RESUMO

The authors examined 29 patients with the syndrome of microvascular angina pectoris. In 12 patients (41.4%) they recorded hyperinsulinaemia as a manifestation of insulin resistance. The body weight, HDL cholesterol level, LDL cholesterol and triglycerides did not differ significantly in the two groups and were at the upper borderline of the range of reference values. The authors analyze mechanisms common to the pathophysiology of the syndrome of microvascular angina pectoris and the syndrome of insulin resistance.


Assuntos
Resistência à Insulina , Angina Microvascular/fisiopatologia , Adulto , Glicemia/análise , Feminino , Humanos , Insulina/sangue , Masculino , Angina Microvascular/sangue , Pessoa de Meia-Idade
19.
Acta Physiol Hung ; 82(3): 257-66, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7717088

RESUMO

Serum contains a factor that can normalize streptozotocin induced blood sugar elevation. This normalization can last for a long period. Thus an elimination of elevated diabetic blood sugar values takes place. This means that an euglycemic factor may have the ability to an eventual curing of diabetes. Normal, starving rats are not influenced by the euglycemic factor. An other factor even aggravates diabetic blood sugar level.


Assuntos
Diabetes Mellitus Experimental/terapia , Animais , Fatores Biológicos/fisiologia , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Proteínas Sanguíneas/fisiologia , Diabetes Mellitus Experimental/sangue , Ratos
20.
Acta Physiol Hung ; 82(2): 181-5, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7887178

RESUMO

In one case of diabetes, normal glucose contents and volumes of the urine and high diabetic values alternate with each other. This periodicity may be of short duration (a couple of days), but long-lasting normal state can also occur. This state of aperiodicity may last almost a month. In such "smoothening" of hormone-regulation, some modulator substances may play a role.


Assuntos
Diabetes Mellitus Tipo 1/complicações , Glicosúria/complicações , Ritmo Circadiano , Diabetes Mellitus Tipo 1/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...