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Biomedical subjects

L M Ruilope

Publications and source records attributed to L M Ruilope.

At least 181 records · Page 10Linked to original sources
PubMed1989

Characterization of the renal effects of an intravenous calcium gluconate infusion in normotensive volunteers.

The effects on renal function of an intravenous infusion of calcium gluconate at subpressor doses have been investigated in a group of seven normotensive male volunteers. In the absence of changes in blood pressure, the calcium gluconate induced a significant increase in renal plasma flow and the glomerular filtration rate (P less than 0.01) with a significant fall in the filtration fraction (P less than 0.01). Both diuresis and natriuresis increased significantly (P less than 0.01), plasma renin activity fell (P less than 0.01) and the urinary excretion of 6-keto prostaglandin F1 alpha (PGF1 alpha) and prostaglandin E2 (PGE2) increased (P less than 0.01). These results indicate that calcium infusion at subpressor doses has renal vasodilating, diuretic and natriuretic properties that appear to be facilitated by an increase in the renal production of vasodilatory and natriuretic prostaglandins.

Adult↗
PubMed1989

Diuretic and natriuretic properties of fenoldopam in chronic renal failure.

The effect of intravenously administered fenoldopam on diuresis and natriuresis was investigated in a group of 10 patients with advanced chronic renal failure. After an initial basal period of 1 h, a fenoldopam infusion was started and maintained for 12 h at rates varying between 0.025 and 0.1 microgram/kg per min. During the study, blood pressure was measured every 10 min and urine volume, natriuresis and creatinine clearance were measured hourly. Fenoldopam induced a significant increase in urine volume, natriuresis and creatinine clearance (P less than 0.05-0.001) accompanied by a small but significant drop in blood pressure (P less than 0.05-0.01). These results show that for advanced chronic renal failure, fenoldopam has diuretic and natriuretic properties that could be of clinical relevance.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1989

Effects of angiotensin converting enzyme inhibitors on the progression of renal failure and proteinuria in humans.

We studied the long-term effect of an angiotensin converting enzyme (ACE) inhibitor, captopril, on the progression of chronic renal failure and on the rate of urinary protein excretion. When compared with standard triple therapy, captopril slowed the progression of renal failure. Captopril was also able to reduce the proteinuria of non-diabetic glomerular origin. This reduction was not dependent on the presence or absence of arterial hypertension but was limited by the presence of low serum albumin levels, and only occurred in patients with proteinuria in excess of 3 g/24 h.

Adult↗
PubMed1989

Effects of nisoldipine on renal function in normal volunteers and essential hypertensive patients.

To evaluate the renal effects of nisoldipine (N), a dihydropyridine derivative, we have evaluated the variations of blood pressure (BP), heart rate, glomerular filtration rate (GFR), renal plasma flow (RPF), 24-h natriuresis, and renal capacity to excrete an i.v. sodium load (2,000 ml isotonic saline in 4-h) in response to a 4-day course of therapy with placebo (P) and N in six normotensive volunteers and six mild-to-moderate essential hypertensive patients. Both volunteers and patients were studied on two constant diets (20 and 150 mEq of sodium daily). No parameters changed after P. On the contrary, N induced a significant fall of BP (p less than 0.01) in the group of patients but not in volunteers. In both groups RPF and GFR increased significantly (p less than 0.05-0.01) while on a low sodium intake but remained constant when sodium intake was high. In the two groups studied, nisoldipine exhibited natriuretic properties manifested by an increase in the 24-h output of sodium as well as by an increased renal capacity to excrete the i.v. sodium load. These natriuretic properties were present in both situations of sodium load and could be facilitated by the change in renal hemodynamics observed when the intake of sodium was low.

Adult↗
PubMed1989

[Comparative prospective randomized multicenter study of 2 dosage protocols of nitrendipine in patients with mild to moderate hypertension].

134 patients with mild to moderate hypertension received nitrendipine during 6 months in an increasing fashion. Therapeutic goal was achieved in 92% of the patients (DBP less than 95 mmHg) in which BP decreased from 168.4 +/- 13.7/105.0 +/- 1.1 to 140.9 +/- 12.7/84.4 +/- 6.6 (p less than 0.001). In patients whose BP was not controlled with a single initial doses of 20 mg/day, the degree of control was similar with 40 mg single dose and 20 mg twice a day. The most frequently encountered undesirable effects were those caused by the vasodilator action of the drug. No changes in blood glucose and plasma lipid levels were found.

Adult↗
PubMed1989

[Clinical characteristics of arterial hypertension in the elderly].

The clinical characteristics of systolic and diastolic hypertension in 75 and of systolic hypertension in 50 elderly patients have been studied and the results have been compared to those obtained in 23 normotense elderly controls and 500 young patients with essential hypertension. A greater incidence in cardiovascular and neurologic morbility was observed in the hypertense elderly, existing also a greater incidence of electrocardiographic abnormalities and impairment in renal function. The changes in blood pressure with postural changes and isometric and physical exercise were evaluated in a subgroup of these patients, finding that the elderly with hypertension, specially those with systolic hypertension, showed orthostatic hypotension, and an increase in blood pressure with exercise, reaching levels that could potentially cause the clinical complications.

Aged↗
PubMed1988

Comparison of the effects of calcium antagonists and converting enzyme inhibitors on renal function under normal and hypertensive conditions.

Calcium antagonists decrease the ability of the kidney to autoregulate renal blood flow (RBF) and glomerular filtration rate (GFR). Therefore, when afferent renovascular resistance is elevated, as in essential hypertension, there is a resultant increase in RBF and GFR with the administration of calcium antagonists. These agents also induce a marked natriuresis because of direct tubular action through unknown mechanisms. The natriuresis can be dissociated from renal and systemic hemodynamic actions, indicating that the decreased sodium reabsorption could override other compensatory mechanisms explaining the absence of sodium retention during the treatment. The renal effects of converting enzyme inhibitors (CEIs) can be explained by the reduction of intrarenal formation in angiotensin II. Because the activation of the renin-angiotensin system is mainly responsible for inducing sodium retention during a decrease in systemic blood pressure, CEIs could have a protecting effect without disturbing other homeostatic mechanisms. CEIs decrease efferent glomerular resistance, reducing capillary pressure and thereby reducing GFR. This effect is not translated in sodium retention because the reduction of GFR is mild during captopril administration in kidneys with normal or increased renal perfusion pressure. At low renal perfusion pressure, the reduced glomerular afferent vasoconstriction can compromise GFR, leading to renal insufficiency. Although these situations are not likely to be encountered during the treatment of uncomplicated essential hypertension, in severe hypertension with hypertrophy of pre-glomerular vessels, glomerular perfusion may decrease. Combination therapy of calcium antagonists and CEIs has been reported to be an effective treatment of severe hypertension. Currently, little information is available on the manner in which renal function is affected by simultaneous administration of both drugs.

Angiotensin II↗
PubMed1988

Improvement in the erythropoiesis of chronic haemodialysis patients with desferrioxamine.

16 chronic haemodialysis patients (group I), with non-microcytic anaemia (mean haemoglobin 7.2 g/dl, SD 1.0, range 5.8-9.8), moderate aluminium overload (serum aluminium 44 micrograms/l, SD 16, range 21-74), and normal or high iron stores (ferritin 800 micrograms/l SD 464, range 34-2013) were treated with intravenous desferrioxamine 1 g at the end of each dialysis for six months. 8 patients with similar characteristics served as controls (group II). After six months group I showed a rise in haemoglobin to 9.1 (SD 2.5) g/dl and a decrease in blood transfusion requirements, both significant, whereas group II showed no changes. Other significant changes observed in group I, but not group II, were a rise in reticulocytes and in red cell creatine and a fall in red cell protoporphyrin and serum ferritin. Ferritin decreased more in the patients whose anaemia improved. Minor increases in serum aluminium in group I did not differ from those in the control group. Desferrioxamine may benefit the anaemia of chronic haemodialysis patients through improvement of erythropoiesis. The effect seems not to be related to chelation of a heavy aluminium overload.

Adult↗
PubMed1988

Renal effects of fenoldopam in refractory hypertension.

Fenoldopam, a dopamine-1 (D1) agonist, was administered by a 6-h intravenous infusion to patients with refractory hypertension [diastolic blood pressure (DBP) greater than 115 mmHg while on triple therapy] in order to achieve a fall in DBP of 30 mmHg. The evolution of blood pressure, heart rate, glomerular filtration rate (GFR), renal plasma flow (RPF), urine volume, renal excretion of sodium, potassium, chloride, calcium, uric acid, phosphate, plasma renin activity (PRA), aldosterone and prolactin were evaluated. A significant fall in blood pressure (P less than 0.01) accompanied by an increase in heart rate (P less than 0.01) was attained after 30 min. GFR and RPF increased significantly (P less than 0.01) but the filtration fraction fell. Urine volume and urinary output of sodium, potassium, chloride, calcium, uric acid and phosphate increased markedly (P less than 0.01). Meanwhile, plasma potassium fell (P less than 0.01) and the hormonal parameters showed no significant change. We concluded that in refractory hypertension fenoldopam has potent renal and systemic vasodilatory properties through which blood pressure falls. The hypotensive effect of fenoldopam is also facilitated by its marked diuretic and natriuretic properties. The absence of variations of plasma prolactin confirm the D1 selectivity of fenoldopam and the lack of increase in PRA indicates that fenoldopam blocks the renin-angiotensin-aldosterone system.

Adult↗
PubMed1988

Control of hypertension with the angiotensin converting enzyme inhibitor captopril reduces glomerular proteinuria.

Recent experimental and clinical data have suggested that angiotension converting enzyme (ACE) inhibitors may decrease glomerular proteinuria by specific effects on the glomerulus. We studied a group of 15 adult patients with chronic renal failure and proteinuria due to various glomerulopathies. These patients had mild to moderate hypertension which was effectively controlled with conventional antihypertensive therapy. We then treated the patients with captopril, maintaining a similar dietary protein and salt intake. After 6 months of study, proteinuria was reduced significantly without reduction in inulin or para-aminohippurate clearance. This supports the concept that captopril may have salutary effects on the glomerulus, independently of its effect on systemic blood pressure.

Blood Pressure↗
PubMed1988

Persistence of the natriuretic effect of calcium entry blockers.

In order to elucidate whether or not the natriuretic properties of calcium entry blockers persist during the long-term administration of the drug, we have investigated the renal capacity to excrete an intravenous sodium load (2,000 ml of isotonic saline in 4 h) in a group of eight mild to moderate essential hypertensive patients, before and after 1, 8, and 24 weeks of treatment with nitrendipine. The following parameters were measured before and hourly during saline infusion: blood pressure, and plasma and urine sodium and potassium. For 5 days prior to the performance of the test, the patients received a diet containing 120 mEq of sodium daily. Nitrendipine induced a significant fall of both systolic and diastolic blood pressure (p less than 0.05-0.01) that was maintained throughout the study. A significant increase of the cumulative renal sodium output (microEq/min/h) was observed after 1, 8, and 24 weeks (p less than 0.05-0.001) of therapy with the calcium entry blocker. Meanwhile, plasma sodium and potassium and the kaliuresis did not change significantly. These results indicate that the natriuretic effect of calcium entry blockers is still present after long-term treatment.

Adult↗