PubMed Health⌕ Search

Biomedical subjects

L M Ruilope

Publications and source records attributed to L M Ruilope.

At least 73 records · Page 4Linked to original sources

The kidney as part of the cardiovascular system.

Renal vascular damage caused by arterial hypertension brings about changes in the systemic vascular function and structure. Nephrosclerosis appears to run in parallel with systemic atherosclerosis, accounting for the increased cardiovascular morbidity and mortality in hypertensive patients. Parameters indicating a change in renal function (increased serum creatinine concentration, proteinuria, and microalbuminuria) are independent predictors of increased cardiovascular morbidity and mortality and must therefore be considered in the classification of cardiovascular risk in hypertensive patients.

Albuminuria↗

AT(1) receptor antagonism reduces endothelial dysfunction and intimal thickening in atherosclerotic rabbits.

The effects of angiotensin (AT)(1) receptor antagonists on functional and morphological alterations associated with atherosclerosis are not well known. The current study was performed to examine the long-term effects of valsartan (3 or 10 mg/kg per day for 10 weeks) on endothelial function and structural changes in aorta from rabbits fed with either a control diet or a cholesterol-enriched diet. Rabbits fed with the cholesterol-rich diet showed higher (P<0.05) plasma levels of cholesterol than did controls. Treatment with valsartan (3 or 10 mg/kg per day) did not alter plasma cholesterol levels or systolic arterial pressure in any group. Contractions induced by angiotensin II were comparable in both control and hypercholesterolemic rabbits and were markedly reduced by treatment with valsartan. Relaxations induced by acetylcholine were lower in hypercholesterolemic rabbits than in controls. Treatment with valsartan (3 or 10 mg/kg per day) enhanced (P<0.05) this response in hypercholesterolemic rabbits but not in controls. Lumen and media cross-sectional areas were comparable in control and hypercholesterolemic rabbits. Vessel area was higher (P<0.05) in hypercholesterolemic rabbits than in controls. Intimal lesion was 29.5+/-6% in cholesterol-fed rabbits and nonexistent in control rabbits. Treatments with 3 and 10 mg/kg per day valsartan reduced (P<0.05) intimal lesion to 2.4+/-0.7% and 2.7+/-0.9%, respectively, and increased lumen area in hypercholesterolemic rabbits. No changes in either vessel or media cross-sectional areas were observed in these animals. In summary, angiotensin II, through AT(1) receptors, appears to play a key role in the development of the vascular functional and structural changes associated with hypercholesterolemia. AT(1) receptor antagonists, besides their antihypertensive effects, could be an important therapeutic tool to reduce the development of atherosclerosis.

Angiotensin I↗

Pressure natriuresis in nitric oxide-deficient hypertensive rats: effect of antihypertensive treatments.

Chronic inhibition of nitric oxide (NO) synthesis has been shown to result in arterial hypertension and an important blunting of the pressure diuresis and natriuresis response (PDN). The mechanisms mediating these abnormalities are not completely understood. In the present study, the role of several antihypertensive drugs to ameliorate these alterations was evaluated. The PDN relationships have been evaluated in rats chronically (8 wk) treated with the NO synthesis inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME; 40 mg/kg per d in the drinking water). Appropriate groups of rats were simultaneously treated with the angiotensin II receptor blocker candesartan at a low (1.5 mg/kg per d) and high (2.5 mg/kg per d) dose, with the converting enzyme inhibitor captopril (60 mg/kg per d) and with the calcium channel blocker verapamil (100 mg/kg per d). Chronic treatment with L-NAME significantly elevated mean BP (163.6 +/- 6.5 mmHg versus 105.1 +/- 3.6 in controls), reduced GFR and renal blood flow (RBF), and shifted to the right the PDN responses. Chronic administration of low-dose candesartan, captopril, or verapamil prevented the arterial hypertension and improved renal hemodynamics, but these levels were not completely normalized. High-dose administration also improved renal hemodynamics but induced reduced BP below the levels of control animals. Despite the normalization of the elevated BP, the PDN responses of these hypertensive treated groups were not normalized, and the slopes of the respective diuretic or natriuretic responses were very similar to those of the hypertensive untreated rats. The results indicate that interruption or blockade of the renin-angiotensin system and calcium channel blockade are effective treatments for the NO-deficient arterial hypertension and renal vasoconstriction. However, the PDN responses are not normalized, and this finding suggests that the antihypertensive treatment is not enough to overcome the renal alterations associated with the chronic deficiency of NO.

Angiotensin-Converting Enzyme Inhibitors↗

Salt sensitivity: concept and pathogenesis.

Almost two decades ago, the existence of a subset of essential hypertensive patients, who were sensitive (according to the increase in blood pressure levels) to the intake of a diet with a high salt content, was described. These patients are characterized by an increase in blood pressure and in body weight when switched from a low to a high sodium intake. The increase in body weight is due to the incapacity of the kidneys to excrete the whole intake of sodium until renal perfusion pressure (mean blood pressure) attains a level that is able to restore pressure-natriuresis relationship to values that enable the kidney to excrete the salt ingested or administered intravenously. Salt sensitivity does not seem to depend on the existence of an intrinsic renal defect to handle sodium, but on the existence of subtle abnormalities in the regulation of the sympathetic nervous system, the renin-angiotensin system or endothelial function. It is also relevant that organ damage secondary to arterial hypertension, has been shown in animal models and in hypertensive humans sensitive to a high salt intake to be significantly higher when compared with that of salt-resistant animals or humans. Interestingly, in humans, salt sensitivity has been shown to correlate with microalbuminuria, an important predictor of cardiovascular morbidity and mortality, which correlates with most of the cardiovascular risk factors commonly associated with arterial hypertension. One of these factors is insulin resistance, that usually accompanies high blood pressure in overweight and obese hypertensives. Insulin resistance and hyperinsulinism are present in a significant percentage of hypertensive patients developing cardiovascular symptoms or death. For these reasons, therapy of arterial hypertension must be directed, not only to facilitate the lowering of BP level, but also, to halt the mechanisms underlying the increase in BP, when salt intake is increased. Furthermore, therapy must preferably improve the diminished insulin sensitivity present in salt-sensitive subjects that contribute independently to increased cardiovascular risk.

Animals↗

Effects of chronic combined treatment with captopril and pravastatin on the progression of insulin resistance and cardiovascular alterations in an experimental model of obesity in dogs.

Obesity is a metabolic disorder in which multiple clinical and biochemical alterations coexist. However, the progression of these alterations in relation to weight gain has not been investigated in detail. Therefore, we studied the evolution of insulin resistance and associated risk factors in a model of experimental obesity in dogs. We also studied whether chronic exposure to these pathogenic factors could induce cardiac and vascular alterations. Twenty male age- and body weight-matched beagle dogs were divided into four groups (n = 5), according to diet and pharmacologic therapy received, and followed for 2 years. Control animals were maintained with a regular diet, while the 15 remaining animals were fed a high-fat diet. The Obese group of dogs received no therapy, whereas the Capto group received 25 mg/12 h captopril, and the Prava+Capto was treated with 10 mg/24 h pravastatin plus the same dose of captopril throughout the study. Periodical determinations of clinical and biochemical parameters were made, and the degree of insulin resistance was also estimated. After the 2-year follow-up, the dogs were killed and vascular thickening in the aorta and the coronary arteries was evaluated. In addition, cardiac hypertrophy was estimated by heart weight and free-wall left ventricular width. Chronic pravastatin plus captopril treatment, together with decreasing weight gain rate, ameliorated the progression of insulin resistance and associated risk factors (hyperinsulinemia, hypercholesterolemia) related to this severe model. In addition, this combined therapy showed cardioprotective action, as cardiac and vascular hypertrophy observed in the Obese group was prevented. These positive results seems to emerge from the synergistic effects of both drugs, as captopril as monotherapy induced only a slight benefit on these parameters.

Animals↗

Factors involved in the effects of losartan on endothelial dysfunction induced by aging in SHR.

In the present study we investigated the effects of losartan (10 mg/kg/day; 12 weeks) on acetylcholine (Ach) induced relaxations in isolated mesenteric vascular beds (MVB) from adult and elderly spontaneous hypertensive rats (SHR). Experiments were done in absence or presence of either the NO synthesis inhibitor, L-NAME (10(-5) mol/liter), L-NAME + indomethacin (10(-5) mol/liter) or L-NAME + indomethacin + KCl (10(-5) mol/liter), to evaluate the participation of the factors (NO, PGs and EDHF, respectively) mediating Ach-relaxations. Systolic blood pressure levels were comparable in both groups. However, urinary nitrites excretion and Ach-response was lower in elderly than in adult SHR. The presence of L-NAME and L-NAME + indomethacin only reduced Ach-relaxations in untreated elderly SHR. Further addition of KCl to the perfusion media totally blunted Ach-relaxation in both groups. The calculated participation of endothelium-derived hyperpolarizing factor (EDHF) in Ach-relaxations was higher than that of nitric oxide (NO) and prostaglandins in both groups, although the EDHF component was lower in elderly when compared to adult SHR. Losartan treatment reduced blood pressure levels and enhanced dose-related Ach-relaxations and urinary nitrites in both groups. Presence of L-NAME and L-NAME + indomethacin blunted the enhancements induced by losartan on Ach-relaxations in both adult and elderly SHR. Further addition of KCl to the perfusion media totally blunted Ach-relaxation in both groups. The calculated participation of NO in Ach-relaxations was increased by losartan in both groups. Neither EDHF or prostanoids (PGs) components were clearly affected by losartan. In conclusion, (1) diminished EDHF availability accounts for the reduced Ach-relaxations produced by aging in MVB from SHR; (2) the enhancement of Ach-relaxations produced by losartan seems to be dependent on an increased NO availability; and (3) angiotensin II via angiotensin I type 1 receptor (AT1) plays an important role in the deleterious consequences of aging on endothelial function in SHR.

Acetylcholine↗

Therapeutic implications and new perspectives for essential hypertension and renal damage.

The kidney can suffer the consequences of a persistently elevated blood pressure. In fact end-stage renal failure caused by essential hypertension appears to be one of the most prevalent etiologies in patients entering a dialysis program. Blood pressure control is needed in order to prevent the progressive loss of renal function. Target blood pressure control has been established at values as low as 125/75 mm Hg for patients with proteinuria above 1 g/day. Attainment of this target level usually requires the combination of two or more drugs. However, the possibility that differences exist among the different classes of antihypertensive drugs beyond their capacity to simply lower blood pressure remains to be clearly elucidated. The fact that the presence of chronic renal failure is also accompanied by an enhanced cardiovascular risk potentiates the need to explore the renoprotective and cardiovascular protective capacity of the different classes of antihypertensive drugs, in patients with essential hypertension and some degree of renal involvement, characterized by the presence of microalbuminuria, proteinuria and/or an elevated serum creatinine.

Antihypertensive Agents↗

Microalbuminuria in essential hypertension.

Microalbuminuria is frequently seen in patients with established essential hypertension, and is a predictor of a higher risk for cardiovascular and probably renal dysfunction. The presence of microalbuminuria has been shown to correlate with the other cardiovascular risk factors commonly seen in hypertensive patients. This fact indicates that the detection of an increased urinary albumin excretion could probably be the best index of an increased global cardiovascular risk in a given patient. Blood pressure control is accompanied by a fall in the content of albumin in urine. Agents with the capacity to block the renin-angiotensin system have shown a capacity to decrease urinary albumin excretion, which is independent of their ability to lower blood pressure. Whether or not a decrease in urinary albumin excretion is accompanied by an improved renal and cardiovascular prognosis in hypertensive patients remains to be elucidated.

Albuminuria↗

The role of combination therapy in the treatment of hypertension.

Antihypertensive therapy is indicated for reducing the risk of cardiovascular morbidity and mortality that accompanies arterial hypertension. Usually, pharmacological treatment is started as monotherapy, which, if unsuccessful, is followed by sequential monotherapy, or by combination therapy. Recent data indicate that combination therapy is required in more than 50% of the hypertensive population when the goal is to reduce blood pressure to below 140/90 mm Hg. The choice and doses of drugs used in combination therapy should be such that their synergistic effect on blood pressure is maximized, the tolerability of the drugs is maintained and side-effects are minimized. The combination of a dihydropyridine calcium antagonist with a beta-blocker or an angiotensin-converting enzyme (ACE) inhibitor is one of the most commonly used combination therapies. Two randomized, double-blind, parallel-group studies compared the antihypertensive effects of the dihydropyridine, barnidipine, with the beta-blocker, atenolol (n = 247), and the ACE inhibitor, enalapril (n = 155). The efficacy and tolerability of barnidipine in combination with either atenolol or enalapril was also investigated. Monotherapy with barnidipine was as effective in reducing blood pressure as monotherapy with either atenolol or enalapril. Combining barnidipine with either atenolol or enalapril reduced blood pressure further, and significantly increased the percentage of patients attaining the required reduction in blood pressure. When patients whose blood pressure was not adequately controlled by enalapril monotherapy were switched to barnidipine monotherapy, the majority then achieved the desired reduction in blood pressure. These results indicate that if barnidipine monotherapy fails to lower blood pressure to the desired values, its combination with either a beta-blocker or an ACE inhibitor is effective and well tolerated.

Antihypertensive Agents↗

Chronic treatment with losartan ameliorates vascular dysfunction induced by aging in spontaneously hypertensive rats.

OBJECTIVE: To evaluate the effects of prolonged treatment with losartan on endothelium-dependent and endothelium-independent relaxations of aortic rings from adult and senescent spontaneously hypertensive rats, and to clarify whether these effects were due to specific mechanisms of the drug or a consequence of its blood-pressure-lowering action. MATERIALS AND METHODS: Adult (aged 5 months) and senescent (aged 20 months) male spontaneously hypertensive rats were treated for 12 consecutive weeks with 10 mg/kg per day losartan. Systolic blood pressure and plasma concentration of nitrates were evaluated. We studied endothelium-dependent and endothelium-independent relaxations and response to angiotensin II of aortic rings from rats of each group. The direct effects of angiotensin II type 1 receptor antagonism on vascular reactivity of aortic rings from untreated adult and senescent rats that had been incubated beforehand with losartan were also studied. RESULTS: Losartan treatment comparably reduced blood pressure and increased plasma concentration of nitrates in rats of both age groups. Responses to acetylcholine and sodium nitroprusside were lower for rings from senescent than they were for rings from adult rats. Constrictor responses to angiotensin II were higher for rings from senescent than they were for rings from adult rats. Treatment with losartan increased the magnitude of relaxations in response to acetylcholine for rings from rats in both groups, but increased the magnitude of relaxations in response to nitroprusside only for rings from senescent spontaneously hypertensive rats. Incubation beforehand of aortic rings from untreated rats with losartan enhanced magnitude of relaxations in response both to acetylcholine and to nitroprusside only for rings from senescent spontaneously hypertensive rats. CONCLUSIONS: The consequences of aging for endothelium-dependent and endothelium-independent relaxations of rings from spontaneously hypertensive rats are ameliorated by losartan treatment, suggesting that angiotensin II plays a role via type 1 receptors. The effects of losartan on senescent spontaneously hypertensive rats were due not only to its blood-pressure-lowering action but also to the blockade of specific mechanisms derived from angiotensin II type 1 receptor antagonism, which might involve an increase in availability of NO.

Aging↗

Blood pressure control, proteinuria and renal outcome in chronic renal failure.

The presence of proteinuria has been shown to be an excellent predictor for a worse outcome of renal function. Both proteinuria and arterial hypertension often coexist in the same patient, and therapy must be directed at decreasing protein excretion in the urine as well as lowering the blood pressure. Any antihypertensive agent has the capacity to lower proteinuria simply by lowering blood pressure. Furthermore, the antiproteinuric capacity of angiotensin-converting enzyme inhibitors can be equalized by other agents or their combination, provided that the fall in blood pressure is great enough. For this reason studies are needed in which the strict control of arterial hypertension combined with a decrease in proteinuria are considered.

Antihypertensive Agents↗

Prognostic value of ambulatory blood pressure monitoring in refractory hypertension: a prospective study.

The objective of this study was to establish whether ambulatory blood pressure offers a better estimate of cardiovascular risk than does its clinical blood pressure counterpart in refractory hypertension. This prospective study assessed the incidence of cardiovascular events over time during an average follow-up of 49 months (range, 6 to 96). Patients were referred to specialized hypertension clinics (86 essential hypertension patients who had diastolic blood pressure > 100 mm Hg during antihypertensive treatment that included three or more antihypertensive drugs, one being a diuretic). Twenty-four-hour ambulatory blood pressure monitoring (ABPM) was performed at the time of entrance. End-organ damage was monitored yearly, and the incidence of cardiovascular events was recorded. Patients were divided into tertiles of average diastolic blood pressure during activity according to the ABPM, with the lowest tertile <88 mm Hg (LT, n=29), the middle tertile 88 to 97 mm Hg (MT, n=29), and the highest tertile >97 mm Hg (HT, n=28). While significant differences in systolic and diastolic ambulatory blood pressures were observed among groups, no differences were observed at either the beginning or at the time of the last evaluation for office blood pressure. During the last evaluation, a progression in the end-organ damage score was observed for the HT group but not for the two other groups. Twenty-one of the patients had a new cardiovascular event; the incidence of events was significantly lower for the LT group (2.2 per 100 patient-years) than it was for the MT group (9.5 per 100 patient-years) or for the HT group (13.6 per 100 patient-years). The probability of event-free survival was also significantly different when comparing the LT group with the other two groups (LT versus MT log-rank, P<.04; LT versus HT log-rank, P<.006). The HT group was an independent risk factor for the incidence of cardiovascular events (relative risk, 6.20; 95% confidence interval, 1.38 to 28.1, P<.02). Higher values of ambulatory blood pressure result in a worse prognosis in patients with refractory hypertension, supporting the recommendation that ABPM is useful in stratifying the cardiovascular risk in patients with refractory hypertension.

Adult↗

How to treat the diabetic hypertensive individual appropriately.

ASSOCIATION OF HYPERTENSION AND DIABETES: Diabetes mellitus and arterial hypertension are closely related and strongly predispose an individual to atherosclerosis and renal failure. Hypertension is twice as frequent in diabetic individuals as it is in the general population, and often precedes the development of diabetic nephropathy. The prevalence of coexisting arterial hypertension and non-insulin-dependent diabetes mellitus is increasing because of ageing of the population, allowing an augmented prevalence of atherosclerosis and end-stage diabetic renal disease. ANTIHYPERTENSIVE TREATMENT OF DIABETIC PATIENTS: The goal of blood pressure control in diabetic patients is to reduce death and disability as much as possible. In addition, other reversible risk factors for cardiovascular disease, which are so frequently seen in hypertensive diabetic individuals, need to be addressed. The optimal blood pressure level in diabetic individuals has not yet been established, but it has been suggested that it be should lower than that recommended by current guidelines. In fact, the literature indicates that 130/85 mmHg should be the systolic/diastolic blood pressure goal in hypertensive diabetic individuals. According to most guidelines the threshold for intervention when multiple associated risk factors coexist with hypertension is a blood pressure level 140/90 mmHg. In diabetic patients therapy has to be instituted early and aggressively. In this regard, angiotensin converting enzyme inhibitors alone or in association with other drugs seem to be the best choice for hypertensive diabetic patients.

Blood Pressure↗

Study population and treatment titration in the International Nifedipine GITS Study: Intervention as a Goal in Hypertension Treatment (INSIGHT).

OBJECTIVES: To ascertain the baseline characteristics of the high-risk hypertensive patients entering the International Nifedipine GITS Study: Intervention as a Goal in Hypertension Treatment (INSIGHT). To determine the success of single and combination therapy in achieving target blood pressures in such a population. DESIGN: INSIGHT is a double-blind, prospective outcome trial comparing the efficacy of the calcium channel blocker, nifedipine GITS, and the thiazide, co-amilozide, in preventing myocardial infarction and stroke. We recruited 2996 men and 3454 women, aged 55-80 years, with blood pressure during placebo run-in >150/95 mmHg or isolated systolic blood pressure >160 mmHg from nine countries. Treatment allocation to nifedipine GITS 30 mg daily or co-amilozide (hydrochlorothiazide 25 mg/amiloride 5 mg) once daily was performed by minimization rather than randomization to balance additional risk factors. This was followed by four optional increases in treatment: dose-doubling of the primary drug, addition of atenolol 25/50 mg or enalapril 5/10 mg, and then any other hypotensive drug excluding calcium blockers or diuretics. Target blood pressure was 140/90 mmHg or a fall > or = 20/10 mmHg. RESULTS: Blood pressure at randomization was 172+/-15 / 99+/-9 mmHg. Thirteen per cent of the patients were previously untreated. The proportions of each additional risk factors were: smoking > 10/day, 29%; cholesterol > 6.43 mmol/l, 52%; family history of premature myocardial infarction or stroke, 21%; diabetes mellitus 20%; left ventricular hypertrophy, 10%; previous myocardial infarction, other presentations of coronary heart disease, and peripheral vascular disease, each 6%; proteinuria, 3%. Fifty-five per cent of patients had one additional risk factor, whereas 33%, 9% and 3% had two, three or more additional risk factors, respectively. The blood pressure (and falls in blood pressure) at the end of titration and at 1 year after minimization was 139+/-12 / 82+/-7 mmHg (33+/-15 / 17+/-9) in the 5226 patients still on randomized treatment The numbers requiring the four treatment increments were, respectively, 1591, 780, 597 and 294, meaning that almost 70% of patients on randomized treatment in INSIGHT are receiving only the primary drug. At one year, 69% of patients had a blood pressure < or = 140/90 mmHg. CONCLUSION: INSIGHT is one of the first double-blind comparisons of active antihypertensive treatments, requiring high-risk patients to achieve sufficient power. Despite this requirement, it is possible to achieve good blood pressure control in most patients without the addition of multiple additional treatments that may dilute any differences between the primary agents.

Aged↗

Effects of cicaprost and fosinopril on the progression of rat diabetic nephropathy.

We have studied the effects of chronic therapy with cicaprost (a PGI2 analog), fosinopril (a converting enzyme inhibitor), and the combination of both drugs on the progression of experimental diabetic nephropathy. Uninephrectomized streptozotocin-induced diabetic rats were maintained for 8 months with plasma glucose between 13.7 and 22.0 mmol/L to hasten renal damage. Systemic and renal parameters were measured periodically, and at sacrifice structural and morphometrical renal studies were performed to evaluate diabetic injury. Control rats exhibited characteristic features of this model, such as high blood pressure and plasma creatinine and urinary albumin excretion, together with prominent alterations in the kidney (renal and glomerular hypertrophies, mesangial matrix expansion, and tubular alterations). The three therapies attenuated equivalently the progression of diabetic renal injury, as estimated by lower urinary albumin excretion, renal and glomerular hypertrophies, and a better renal architectural preservation. No synergistic action was appreciated with the combined therapy. However, renal preservation achieved with cicaprost was not linked to reductions in systemic blood pressure, whereas in the groups treated with fosinopril the hypotensive effect of this drug could have contributed to the positive outcome of the therapy. Therefore, nephroprotection exerted by this PGI2 analog in this model seems more related to the derangement of renal local mechanisms than to systemic blood pressure control. Finally, the possibility that an impaired prostacyclin synthesis or bioavailability is involved in the pathogenesis of the diabetic nephropathy in this model underlies our results.

Albuminuria↗

Nitric oxide, the kidney, and hypertension.

The acute administration of nitric oxide (NO) synthesis inhibitors reduces the renal capacity to excrete sodium under normal or volume expanded conditions and increases renovascular resistances in the absence of changes in systemic blood pressure (BP). This indicates a sensitivity of renal vasculature higher than that of systemic vessels to NO synthesis inhibition. Medullary circulation is the renovascular territory most dependent on NO availability. Thus, alterations in medullary blood flow seems to account for the blunted pressure-natriuresis and sodium retention during acute NO synthesis inhibition. By contrast, during chronic administration of L-arginine analogs, systemic BP rises and overrides initial sodium retention by a resetting of the pressure-natriuresis relationship. This BP increase appears to be dependent on an overexpression of the actions of vasoconstrictor systems due to an imbalance created by the diminished NO production. Prolonged NO synthesis inhibition not only elevates BP, but also produces renal vascular and parenchymal damage. Antihypertensive therapy impedes BP elevation and ameliorates kidney deterioration. Finally, there is evidence of the possibility that a certain alteration in the L-arginine-NO pathway exists in genetic models and in human essential hypertension. In conclusion, according to the data contained in the literature, NO plays a significant role in the regulation of systemic and renal hemodynamics and excretory function, and could participate in the development of hypertension.

Animals↗