EFICACIA E TOLERABILIDADE DA ASSOCIACAO CAPTOPRIL + HIDROCLOROTIAZIDA NO TRATAMENTO DA HIPERTENSAO ARTERIAL LEVE A MODERADA. ESTUDO MULTICENTRICO

Purpose. To evaluate the antihypertensive efficacy and tolerability of captopril 50 mg + hydrochlorothiazide 25 mg daily in mild to moderate primary hypertension. Methods. Out-patients (n = 471) with mild to moderate hypertension, diastolic blood pressure (DBP) 95-115 mmHg, with 15 days of washout, were included to the treatment initially with half tablet of the association of captopril 50 mg + hydrochlorothiazide 25 mg once daily, for 30 days. After this period, patients with DBP > 90 mmHg had the dosage duplicated, while the others had the same dosage for 60 days more. Evaluation was performed 15 days before and then every month during active drug. Results. Twenty six patients were withdrawn, 13 (2,7%) by adverse effects and 13 by protocol violation. At the end of the wash-out period, the blood pressure (BP), 162 ± 16/103 ± 6 mmHg decreased significantly at the 30th day to 146 ± 14/92 ± 8 mmHg (p < 0,001 vs 0th day); 139 ± 12/86 ± 7 mmHg at the 60th day, (p < 0,001 vs 30th day), and further to 136 ± 11/84 ± 5 mmHg (p < 0,001 vs day 0) till the end of the 90th day. Antihypertensive efficay (DBP ≤ 90 mmHg and decreased for the DBP ≥ 10 mmHg) was obtained in 82% of the patients. There was no difference in BP control considering race, hypertension level, previous antihypertensive treatment and obesity. Cough (4%) was the main adverse event. Conclusion. Captopril + hydrochlorothiazide was effective and safe in the treatment of mild to moderate hypertension. The favorable response was observed in 82% of the patients independently of race, hypertensive level, previous antihypertensive treatment and obesity. Low incidence of side effects was reported, with no difference from others reported in the literature.

Effects of intracerebroventricular injections of losartan or PD123319 on arterial pressure and heart rate of sodium replete and sodium deplete rats

Angiotensin II (Ang II) non-peptide antagonists were injected i.c.v. (6.25-200 nmol, n = 5-8 rats/group): In sodium replete rats, losartan (AT1 receptor antagonist) induced an increase in mean arterial pressure (MAP) and in heart rate (HR) by 3rd ventricular (3rdV) injection, and a weaker pressor response and bradycardia by 4th ventricular (4thV) injection. PD123319 (AT2 receptor antagonist) induced an increase in MAP and in HR by 3rdV injection, and an increase in MAP and no alteration in HR by 4thV injection. In sodium deplete (furosemide plus removal of ambient sodium for 24 h) rats, losartan induced an increase in MAP and no alteration in HR by 3rdV injection, and no alteration in MAP and bradycardia by 4thV injection. PD123319 induced an increase in MAP and in HR by 3rdV injection, and an increase in MAP and bradycardia by 4thV injection. Thus, there was no fall in MAP by central injections of Ang II antagonists. Intravenous injection of losartan, but not of PD123319, induced a fall in MAP in both sodium replete and sodium deplete animals. Therefore, losartan and PD123319 can have similar effects on MAP and HR when injected intracerebroventricularly, although some differences are also present. The bradycardia is consistent with an withdrawal of Ang II inhibitory action on baroreflex.

Influencia da elevacao sustentada da pressao arterial sobre a dP/dt do ventriculo esquerdo mantendo-se constante a pressao diastolica do ventriculo esquerdo

Purpose - To evaluate the influence of sustained elevations of arterial pressure on dP/dt values, which the left ventricular end diastolic pressure was kept constant. Methods - Thirteen anesthetized dogs, mechanically ventilated and submitted to thoracotomy and pharmacological autonomic block (atropine - 0.5 mg/kg IV + oxprenolol - 3 mg/kg IV) were studied. The arterial pressure elevation was obtained by mechanical constriction of the descending thoracic aorta. Analyses were made in control (C) situation and after two successives increments of arterial pressure, sustained for 10min, called hypertension 1 (H1) and hypertension 2 (H2), respectively. The end diastolic left ventricular pressure was kept constant by utilization of a perfusion system connected to the left atria. Results - Heart rate did not change (C: 125 ± 13.9bpm; H1: 125 ± 13.5bpm; H2: 123 ± 14.1bpm; p > 0.05); the LVSP increased (C: 119 ± 8.1mmHg; H1: 142 ± 7.9mmHg; H2: 166 ± 7.7mmHg; p < 0.01); the AoDP increased (C: 89 ± 11.6mmHg; H1: 99 ± 9.5mmHg; H2: 120 ± 11.8mmHg; p < 0.01); the LVEDP (C: 6.2 ± 2.48mmHg; H1: 6.3 ± 2.43mmHg; H2: 6.1 ± 2.51mmHg; p > 0.05) and the dP/dt (C: 3068 ± 1057.1mmHg/s; 3112 ± 995.7mmHg/s; H2: 3086 ± 979.5mmHg/s; p > 0.05) did not change. Conclusion - dP/dt values are not influenced by a sustained elevation of arterial pressure, when the end diastolic left ventricular pressure is kept constant.

Efeito de drogas utilizadas no tratamento de hipertensão arterial sistêmica sobre a pressão intra-ocular: Estudo experimental no cão

Purpose: To study the effects of two drugs (captopril and propranolol) used in the treatment of systemic hypertension, on the intraocular pressure (IOP) of anesthetized dogs. Methods: 24 dogs, divided into 3 groups of 8 each. In the first group, 1.5 mg/kg IV of captopril (an angiotensin converting enzyme inhibitor) was administered. In the second group, 1.5 mg/kg IV of propranolol (a beta-blocker) was administered. The third group was the control. IOP and blood pressure (BP) were measured by manometry. The perfusion pressure was calculated by the difference between BP and IOP (BP-IOP). The parameters were studied at 6 moments (0, 10, 30, 60, 90 and 120 minutes). Results: There was significant reduction of IOP (p<0.05) with captopril and propranolol, without difference between the drugs. With captopril the BP and PP decreased markedly at 10 and 30 minutes. With propranolol there was no reduction of BP or PP. Conclusions: Captopril and propranolol reduced IOP. However, the marked reduction of BP, and consequently of PP caused by captopril may be undesirable for irrigation of the optic nerve.

Independent impact of glycemia ad blood pressure in albuminuria on high-risk subjects for metabolic syndrome

Background: Microalbuminuria may reflect diffuse endothelial damage. Considering that diabetes and hypertension cause vasculopathy, we investigated associations of albumin-to-creatinine ratio (ACR) with plasma glucose and blood pressure levels in high-risk subjects for metabolic syndrome. Methods: A sample of 519 (246 men) Japanese-Brazilians (aged 60 ± 11 years), who participated in a population-based study, had their ACR determined in a morning urine specimen. Backward models of multiple linear regression were created for each gender including log-transformed values of ACR as dependent variable; an interaction term between diabetes and hypertension was included. Results: Macroalbuminuria was found in 18 subjects. ACR mean values for subjects with normal glucose tolerance, impaired fasting glycemia, impaired glucose tolerance and diabetes were 9.9 ± 6.0, 19.0 ± 35.4, 20.7 ± 35.4, and 33.9 ± 55.0 mg/g, respectively. Diabetic subjects showed higher ACR than the others (p < 0.05). An increase in the proportion of albuminuric subjects was observed as glucose metabolism deteriorated (4.9, 17.0, 23.0 and 36.0%). Stratifying into 4 groups according to postchallenge glycemia (< 7.8 mmol/l, n = 9 1; ≥ 7.8 mmol/l, n = 4 10) and hypertension, hypertensive and glucose-intolerant subgroups showed higher ACR values. ACR was associated with gender, waist circumference, blood pressure, plasma glucose and triglyceride (p < 0.05); albuminuric subjects had significantly higher levels of such variables than the normoalbuminuric ones. In the final models of linear regression, systolic blood pressure and 2-hour glycemia were shown to be independent predictors of ACR for both genders (p < 0.05). In men, also waist was independently associated with ACR. No interaction was detected between diabetes and hypertension. Conclusions: These findings suggest that both glucose intolerance and hypertension could have independent but not synergistic effects on endothelial function - reflected by albumin loss in urine. Such hypothesis needs to be confirmed in prospective studies. © 2004 Dustri-Verlag Dr. K. Feistle.

Efeitos do extrato aquoso de cebola (Allium cepa L.) sobre a função renal e a pressão arterial em ratos Wistar

The vegetal species, Allium cepa, known as onion, is widely used in the folk medicine as diuretic, besides it has been used on the bronchitis, cough, cardiovascular diseases and hypertension treatment. In this study we evaluate the onion aqueous extract (AE) effect on water flow and electrolytes in anesthetized Wistar rats, besides we also evaluate arterial pressure alterations. Two groups were studied: Group 1 (control) - oral tratment with 1.0 mL of distilled water, and Group 2 (experimental) - oral treatment with 1.0 mL of AE 20%. The rats were anesthetized and we canulate the trachea, left carotide artery (for arterial pressure measurement and blood collecting), jugular vein (to execute inulin perfusion - to register glomerular filtration), and urinary bladder (to collect urine). The Group 1 results had shown that the animals had not presented significant alterations (p>0.05) in the analyzed parameters. The animals of Group 2 had a significant reduction (p<0.05) in the arterial pressure (22.0%). However, there were not significant alterations in renal parameters (p>0.05). These results show that the treatment with the AE lead a hypotensor effect in anesthetized Wistar rats, but not followed by renal parameters alterations.

O óxido nítrico (NO) no controle neural da pressão arterial: Modulação da transmissão glutamatérgica no NTS

The neuromodulatory effect of nitric oxide (NO) on glutamatergic transmission within the NTS related to cardiovascular regulation has been widely investigated. Activation of glutamatergic receptors in the NTS stimulates the production and release of NO and other nitrosyl substances with neurotransmitter/neuromodulator properties. The presence of NOS, including the protein nNOS and its mRNA in vagal afferent terminals in the NTS and nodose ganglion cells suggest that NO can act on glutamatergic transmission. We previously reported that iontophoresis of L-NAME on NTS neurons receiving vagal afferent inputs significantly decreased the number of action potentials evoked by iontophoretic application of AMPA. In addition, iontophoresis of the NO donor papaNONOate enhanced spontaneous discharge and the number of action potentials elicited by AMPA, suggesting that NO could be facilitating AMPA-mediated neuronal transmission within the NTS. Furthermore, the changes in renal sympathetic discharge during activation of baroreceptors and cardiopulmonary receptors involve activation of AMPA and NMDA receptors in the NTS and these responses are attenuated by microinjection of L-NAME in the NTS of conscious and anesthetized rats. Cardiovascular responses elicited by application of NO in the NTS are closely similar to those obtained after activation of vagal afferent inputs, and L-glutamate is the main neurotransmitter of vagal afferent fibers. In this review we discuss the possible neuromodulatory mechanisms of central produced/released NO on glutamatergic transmission within the NTS.

Espécies reativas de oxigênio no controle neurovegetativo da pressão arterial

The control of the blood pressure depends on the activity of select groups of neurons present in the central nervous system. Evidence has demonstrated that the redox state (a balance between oxidizing and reducing species) is involved in the control of neuronal activity, which suggests that the redox state can influence the neuronal transmission within the central nervous system acting on the neuronal modulation of biological functions. For instance, the glutamatergic transmission may be widely affected by reactive oxygen species, oxidizing agents that have been extensively investigated due to their involvement in physiological and pathological processes. In the present article, we discuss the main experimental finds that support the hypothesis that reactive oxygen species have important role in physiological (and pathological) modulation of the cardiovascular function through alterations in the sympathetic and parasympathetic system. Therefore, reactive oxygen species can actively participate in the development of cardiovascular diseases like hypertension when the balance in the redox state is disrupted.

Estudo comparativo da pressão arterial sistêmica obtida por dois métodos distintos

As arterial hypertension can be diagnosed by different methods, among which are the traditional auscultatory instrument and the automated oscillometric monitor, the aim of this study was to compare the performance of these instruments, to evaluate the reliability of the digital oscillometer. The sample consisted of 40 patients under dental treatment, whose blood pressure measurements were recorded. The measurements of systolic and diastolic blood pressures were evaluated in terms of their intraclass correlation coefficients (r). For systolic blood pressure, an excellent level of agreement was found between the instruments, with r=0.93, and for diastolic blood pressure, there was a good level of agreement (r=0.75). It was concluded, from the excellent agreement for systolic blood pressure, that the oscillometric monitor can be recommended for the monitoring of the variations of that pressure in the same individual, while the good agreement obtained in the determination of the diastolic blood pressure indicates that the oscillometric method is reliable. However, new studies need to be carried out for a better understanding of the disagreements that can occur in the diastolic pressure results.

Influence of endogenous and synthetic female sex hormones on human blood cells in vitro studied with comet assay

The comet assay has been conducted with numerous cell lines to assess in vitro genotoxicity. In order to use the comet assay as part of an in vitro test for evaluating genotoxicity, however, there are cell-specific factors that need to be better understood. In this present study we have evaluated some factors that may impact upon the DNA damage detected in whole blood (WB) cells and lymphocytes (ILs). Experiments were conducted comparing responses of both cells, and investigating the effects of the female hormonal cycle, and oral contraceptive (OC) use on DNA damage detection in the in vitro comet assay, at three sampling time. No significant differences were detected in the basal levels of DNA damage detected in ILs and WB cells from women OC users and non-users and from men. Basal DNA damage in ILs was unaffected by gender and stage of the menstrual cycle or the stage of the treatment schedule. Our results also indicated that the H2O2 induces DNA damage in human lymphocytes independently of gender, low-dose OC use and hormonal fluctuation. However, data showed that in 3rd sampling of menstrual cycle, lymphocytes were more resistant to H2O2-induced DNA damage than those from OC users and men. © 2007 Elsevier Ltd. All rights reserved.

Comparação entre hipertensão autoreferida e pressão arterial casual e presença de fatores de risco em funcionários da saúde Bauru e Jaú

Model: Prevalence study. Objectives: To evaluate the presence of self-reported hypertension to compare with blood pressure measurements. Besides, this work investigated health information level of workers and if the job position has any influence on blood pressure (BP). Methods: This study evaluated 349 health workers (44±10 years old) from Bauru and Jau cities, who answered some questions about history of health condition, use of medicines, past surgeries as well as social, scholar and physical conditions and had their blood pressure measured. Each subject selfreported as normotensive or hypertensive. Values of systolic ≥ 140 mmHg and/or diastolic PA ≥ 90 mmHg were considered elevated. Among the health workers evaluated, 198 were submitted to anthropometric and biochemical evaluations. Values are presented as means ± SD and frequency of distribution. It was used T-student test (p<0.05). Results: From all workers evaluated only 16% self-reported as hypertensive, which 56% presented high BP, however 91% used to take antihypertensive medicines. Among the 84% who self-reported as normotensive, 24% presented high BP and 8% used to take medicines. Although most of the employees of each section self-reported as normotensive, more than a half presented high BP and which was more common in the health's section (76.3%). Conclusion: These results suggest that besides the majority of the employees self-reported as normotensive, an elevated number of health workers presented high blood pressure and used to take medicines inappropriately, which indicates that they did not have enough knowledge about their health. Furthermore, it was observed that Health Section presented the higher blood pressure values.

Características da hipertensão arterial em Unidade Básica de Saúde

A cross observational study was achieved about hypertensive patients from the Basic Health Unit in Betel, Paulinia - S.P. assessing blood pressure levels, anthropometric data, biosocial variables, responses to questionaires about physical activity (Ipaq), and quality of life (Whoqol), as well as estimates of cardiovascular risk by Framingham score. With descriptive purposes, absolute and relative frequencies distributions are presented. From originally 95 people in the study, 18 were eliminated, and the remaining 77 were predominately composed by women, averaged 55.87 years old (standard deviation 11.88); white ethnic; basic schooling education, and income of 3 minimum salaries. Although clinical criteria verified altered values, it was the physical evaluation that indicated more clearly risks of contracting cardiovascular diseases, thus showing how different complementary evaluations can better predict risk. These results demonstrated that other professionals should be an asset as an integral part of the health team. © Copyright Moreira Jr. Editora. Todos os direitos reservados.

An assessment of a sequence of yoga exercises to patients with arterial hypertension

This quasi-experimental study describes the effects of a yoga sequence following hemodynamic and biochemical parameters in patients with hypertension. Thirty-three volunteers participated in the study (control = 16 and yoga = 17) for four months. Blood pressure measurements, cardiac and respiratory rate were collected monthly, while the biochemical profile was taken at the beginning and end of the program. To analyze the data, Student's t test and repeated measures analyses were performed. The yoga group showed a significant reduction of systolic blood pressure, heart and respiratory rate (p < 0.05). As for the biochemical profile, the yoga group showed correlation coefficients between initial values and final responses greater than the control of fasting glucose, total cholesterol, LDL-cholesterol and triglycerides. The elaborated sequence practice promoted significant cardiovascular and metabolic benefits. The yoga exercises performed in the proposed sequence constitute complementary non-pharmacological control of blood pressure in patients with hypertension. © 2012 Elsevier Ltd.

Control of breathing and blood pressure by parafacial neurons in conscious rats

New Findings: • What is the central question of this study? The main purpose of the present manuscript was to investigate the cardiorespiratory responses to hypoxia or hypercapnia in conscious rats submitted to neuronal blockade of the parafacial region. We clearly showed that the integrity of parafacial region is important for the respiratory responses elicited by peripheral and central chemoreflex activation in freely behavior rats. • What is the main finding and its importance? Since the parafacial region is part of the respiratory rhythm generator, they are essential for postnatal survival, which is probably due to their contribution to chemoreception in conscious rats. The retrotrapezoid nucleus (RTN), located in the parafacial region, contains glutamatergic neurons that express the transcriptor factor Phox2b and that are suggested to be central respiratory chemoreceptors. Studies in anaesthetized animals or in vitro have suggested that RTN neurons are important in the control of breathing by influencing respiratory rate, inspiratory amplitude and active expiration. However, the contribution of these neurons to cardiorespiratory control in conscious rats is not clear. Male Holtzman rats (280-300 g, n= 6-8) with bilateral stainless-steel cannulae implanted into the RTN were used. In conscious rats, the microinjection of the ionotropic glutamatergic agonist NMDA (5 pmol in 50 nl) into the RTN increased respiratory frequency (by 42%), tidal volume (by 21%), ventilation (by 68%), peak expiratory flow (by 24%) and mean arterial pressure (MAP, increased by 16 ± 4, versus saline, 3 ± 2 mmHg). Bilateral inhibition of the RTN neurons with the GABAA agonist muscimol (100 pmol in 50 nl) reduced resting ventilation (52 ± 34, versus saline, 250 ± 56 ml min-1 kg-1 with absolute values) and attenuated the respiratory response to hypercapnia and hypoxia. Muscimol injected into the RTN slightly reduced resting MAP (decreased by 13 ± 7, versus saline, increased by 3 ± 2 mmHg), without changing the effects of hypercapnia or hypoxia on MAP and heart rate. The results suggest that RTN neurons activate facilitatory mechanisms important to the control of ventilation in resting, hypoxic or hypercapnic conditions in conscious rats. © 2012 The Authors. Experimental Physiology © 2012 The Physiological Society.