Usefulness of preoperative echocardiography in predicting left ventricular outflow obstruction after primary repair of interrupted aortic arch with ventricular septal defect

OBJECTIVE: "Renal dose" dopamine is widely used in the perioperative period to provide renal protection. A comprehensive review of the literature was performed to determine whether dopamine does in fact confer protection on the kidneys of surgical patients. SUMMARY BACKGROUND DATA: Studies in healthy animals and human volunteers reveal that dopamine causes diuresis and natriuresis, as well as some degree of renal vasodilatation. RESULTS: Studies of the perioperative use of dopamine fail to demonstrate any benefit of dopamine in preventing renal failure. Studies in congestive heart failure, critical illness, and sepsis also fail to show any benefit of dopamine other than diuresis. Further, dopamine administration is not completely without risk, because of dopamine's catecholamine and neuroendocrine functions. CONCLUSIONS: Routine use of prophylactic "renal dose" dopamine in surgical patients is not recommended.     

Renal effects of angiotensin converting enzyme inhibitors in heart failure: a clinician's guide to minimizing azotemia and diuretic-induced electrolyte imbalances

Angiotensin converting enzyme (ACE) inhibitors have proved to be valuable, life-saving medications in the management of heart failure. While reducing myocardial oxygen consumption, they increase cardiac output and thus renal plasma flow. Despite reports in the literature of adverse effects of these drugs on renal function, the risks of functional deterioration are predictable in patient populations and remediable. Patients at greatest risk of declining renal function during therapy with ACE inhibitors are those in whom maintenance of renal function is dependent on angiotensin II. Reducing the dose of the concomitant diuretic, liberalizing the dietary intake of sodium, and increasing the dose of the ACE inhibitor usually restores renal function to baseline. In patients with severe renal insufficiency, reducing the dose of the ACE inhibitor might be necessary to preserve the glomerular filtration rate.     

Renal hemodynamics during norepinephrine and low-dose dopamine infusions in man

OBJECTIVE: To characterize the effects of pressor doses of norepinephrine and low-dose dopamine (3 micrograms/kg/min) on renal hemodynamics in man, as well as to determine the clinical relevance of combining dopamine with norepinephrine. DESIGN: Prospective, single-blind, randomized study. SETTING: Clinical research unit of a tertiary care hospital. SUBJECTS. Six healthy male volunteers ranging in age between 20 and 28 yrs. INTERVENTIONS: The subjects were assigned randomly to four treatments (1 wk apart) in which renal hemodynamics and electrolyte excretion were assessed. Treatments consisted of 180-min infusions of the following: a) 0.9% sodium chloride (control); b) pressor doses of norepinephrine; c) dopamine at 3 micrograms/kg/min; and d) pressor doses of norepinephrine and dopamine at 3 micrograms/kg/min. Pressor doses of norepinephrine was defined as doses required to increase mean arterial pressure (MAP) by 20 mm Hg. MEASUREMENTS AND MAIN RESULTS: Glomerular filtration rate and renal blood flow were derived from inulin and para-aminohippurate clearances, respectively. Urine output and urine solute excretion were also determined. The mean norepinephrine dose required to increase MAP by 22 +/- 2 mm Hg was 118 +/- 30 ng/kg/min (range 76 to 164). After the addition of dopamine, similar doses of norepinephrine resulted in an MAP increase of 15 +/- 4 mm Hg. Glomerular filtration rate and urine output were comparable under all conditions. The infusion of norepinephrine decreased renal blood flow from 1241 +/- 208 to 922 +/- 143 mL/min/1.73 m2 (p = .03). The addition of dopamine returned renal blood flow to baseline values. The clearance of urine sodium increased significantly with the infusion of dopamine alone (p = .03). All subjects completed the four treatment periods. Adverse events, manifested mostly as palpitations and flushing, were rare and self-limiting. CONCLUSIONS: The addition of dopamine (3 micrograms/kg/min) to pressor doses of norepinephrine normalized renal blood flow in healthy volunteers. These hemodynamic changes were not reflected in urine output and glomerular filtration rate; hence, these monitoring parameters may be unreliable indicators of renal function in the setting of vasopressor therapy. In addition, systemic effects were observed with dopamine (3 micrograms/kg/min), as indicated by a decrease in MAP.     

The dobutamine-dopamine combination versus amrinone in congestive heart failure with a marked edematogenic sign complicated by functional kidney failure. A comparison between 2 different models of inotropic stimulation and diuresis potentiation

BACKGROUND: We evaluated the diuretic output in patients with decompensated chronic heart failure (CHF), previously treated by i.v. infusion with dobutamine and dopamine (dob-dop) or with amrinone (amr). Our target was to identify the possible discrepancies in urinary output perhaps linked to the different type of inotropic stimulation in the two subsets. METHODS: Adjunctive therapy with dob-dop or amr was chosen because the administration of diuretics only, without cardiac support, as tested in previous hospitalizations, had been demonstrated to produce unfavourable results, mainly expressed by finding of a low output syndrome in 50% of cases or more. The administration of i.v. infusion was maintained during 17 hours (1000 min approximatively), and included infusion in separate pumps of the two amines, dobutamine at dose of 5 micrograms/kg/min and dopamine at dose of 2.8 micrograms/kg/min or, alternatively, i.v. infusion of amr, administered at dose of 7 micrograms/kg/min. Infusion volumes were similar in the two subsets. The two subsets were homogeneous relatively to renal impairment, i.e. to the parameters (urinary Na, U/P creatinine, U/P urea, urinary osmolality) we fixed as markers idoneous to demonstrate the occurrence of organic renal damage (acute tubular necrosis). RESULTS: The diuresis was recovered in all 24 patients, and the urine volume resulted more pronounced in the subset attributed to the dob-dop at both the 8th and the 17th hour readings. We found no harmful alterations in HR and AP, whereas renal function parameters have been shown to enhance in both the dob-dop and amr arms. The diuretic effectiveness of the SIEV obtained by catecholamine implementation exercised a synergistic, favourable effect on diuresis, renal flow, glomerular filtration rate, and sodium post-proximal delivery. Amr resulted less effective then dob-dop simultaneous administration relatively to the diuretic effect. No remarkable differences were found in the two subsets as regards the heart rate, whereas a decrease in arterial pressure was found after amr. A persistent shift towards a condition of chronic renal failure, was identified in 4/24 patients, the two groups despite of the prolonged treatment at optimized doses: no remarkable side effects were reported. CONCLUSIONS: Thus, the selective effect upon renal hemodynamics, as exercised by dob-dop infusion low doses of dop, together with the enhanced renal output due to dob, has been shown to be more effective than amr influence: thus, the catecholamine therapeutical approach has been demonstrated to possess the best effectiveness in excitation of diuresis, among the CHF oliguric patients.     

Recurrent urinary tract infections. Biological suppositions and clinical treatment with thymopentin]

We estimated the glomerular filtration rate in 33 patients from our diabetic clinic using three methods: the creatinine clearance measured from a timed urine sample and a serum creatinine; the creatinine clearance calculated from the serum creatinine according to the formula of Cockcroft and Gault; and, the plasma clearance of ethylenediaminetetra-acetic acid (EDTA) labeled with 51Cr ([51Cr]EDTA). We repeated the measurements in seven subjects. The measured creatinine clearance was not reproducible. The other two methods were correlated, but not according to the formula y = x. The calculated creatinine clearance significantly underestimated the [51Cr]EDTA clearance particularly at higher [51Cr]EDTA clearance rates. [51Cr]EDTA clearance has been shown by others to parallel, but underestimate, inulin clearance, the optimal method of estimating glomerular filtration rate but difficult to perform in routine practice. Accurately measuring renal function in routine clinical practice is difficult, and this must be borne in mind when making clinical decisions based on current measurements.     

Diagnosis of thoracic outlet syndrome in the emergency department

Gadodiamide at a dose of 0.1 mmol/kg was administered intravenously to 10 renal transplanted patients with stable, impaired, or slowly deteriorating renal function (serum creatinine 194-362 mumol/l). The patients were referred for contrast medium enhanced magnetic resonance imaging to rule out possible graft circulation abnormalities. The excretion of gadodiamide in urine was prolonged as compared with healthy controls. After 120 h 92% of the injected dose was excreted in urine and only 0.4% in faeces. The plasma clearance of gadodiamide was 28.6 +/- (SD) 5.5 ml/min (n = 10), and the renal clearance (0-72 h) was 26.3 ml/min. The renal clearance of 125I-iothalamate for the same time period was 27.9 +/- 5.3 ml/min. Thus, gadodiamide is eliminated by glomerular filtration also in renal transplant patients with moderately to severe impaired renal function, and gadodiamide clearance may serve as an alternative marker for the determination of the glomerular filtration rate. Serum values of creatinine and beta(2)-microglobulin and creatinine clearance were unchanged by gadodiamide and neither was the urinary enzyme excretion significantly changed. These results suggest that the renal tolerance to gadodiamide is good also in renal transplant patients with impaired renal function.     

Significance of the karyopyknotic index in the course control of hormone-treated prostatic carcinoma

Renal function was evaluated in 40 patients with fulminant hepatic failure, They were divided into two groups on the basis of glomerular filtration rates greater than 40 ml/min or less than 25 ml/min. A number of patients in group 1 had markedly abnormal renal retention of sodium together with a reduced free water clearance and low potassium excretion which could be explained by increased proximal tubular reabsorption of sodium. The patients in group 2 had evidence that renal tubular integrity was maintained when the glomerular filtration rate was greater than or equal ml/min (functional renal failure), but evidence of tubular damage was present when this was less than 3 ml/min (acute tubular necrosis).     

The effects of an angiotensin blocker (saralasin) on kidney function in dehydrated sheep

Saralasin, an angiotensin II analogue and receptor blocker, was infused at 7 and 15 micrograms . min-1 into dehydrated conscious Merino ewes. This caused mean arterial blood pressure, cardiac output, heart rate and renal vascular resistance to fall, and central venous pressure to rise. Renal plasma flow was unaffected but there were significant reductions in glomerular filtration rate, filtration fraction, urine flow, sodium and potassium excretion, solute clearance and solute-free water reabsorption. It is suggested that saralasin produced these effects by inhibiting endogenous angiotensin II activity, and in particular by causing a reduction in renal post-glomerular resistance. This in turn caused a fall in glomerular filtration rate and filtration fraction. While saralasin might have had effects on renal tubular function and perhaps on vasopressin secretion, the observed effects on renal function can be explained by the decrease in glomerular filtration rate and filtration fraction.     

Assessing renal effects and renal protection

ASSESSMENT OF RENAL FUNCTION: There are a number of methods of evaluating renal function, including measurements of glomerular filtration, renal plasma flow, tubular function, micro- and macroalbuminuria and urinary sediment. Of these, microalbuminuria, glomerular filtration and renal plasma flow are the most appropriate. RENAL EFFECTS OF CALCIUM ANTAGONISTS: Calcium antagonists have important effects on renal function, including a reduction in renal vasoconstriction, increased renal blood flow and, in some circumstances, reduced protein excretion. In particular, these agents can reverse the mild renal vasoconstriction that is seen in the offspring of hypertensive patients. The renal effects of calcium antagonists have been studied in animal models, where radioimaging techniques have shown a biphasic haemodynamic response. RENAL PROTECTION WITH CALCIUM ANTAGONISTS: Two important beneficial effects of calcium antagonists are prevention of acute renal failure and protection against cyclosporin nephrotoxicity. Calcium antagonists have thus been used therapeutically in renal transplant patients and in patients with acute renal failure secondary to the effects of nephrotoxic agents.     

High-dose therapy including carboplatin adjusted for renal function in patients with relapsed or refractory germ cell tumour: outcome and prognostic factors

Thirty-one consecutive patients with relapsed or refractory GCT received an HDT schedule including carboplatin, the dose of which was adjusted to measured glomerular filtration rate. There was one HDT-associated death (3%), due to acute renal failure. The 3-year probability of overall and disease-free survival for 21 patients with primary refractory disease or responsive relapse was 60% and 42%, respectively, while none of ten patients with refractory relapse have survived disease free.     

Effect of intravenous furosemide on the renal excretion of digoxin

The effect of an 80-mg intravenous dose of furosemide on the urinary excretion of digoxin was determined in three adult men with normal renal function, each of whom was taking 0.25 mg digoxin daily on a chronic basis. On two separate days, serum samples were taken and urine was collected every 2 hours over an 8-hour period for determination of digoxin, creatinine, calcium, and sodium concentrations. On the first day of study, a saline bolus was given intravenously, and on the second day, furosemide was given. In all subjects, urinary digoxin excretion increased after furosemide in direct proportion to the increase in urine volume. No consistent correlation was seen between digoxin excretion and creatinine, calcium, or sodium output. No significant changes in serum digoxin were found in this active study. These results are consistent with the hypothesis that increasing glomerular filtration rate or total urine volume increases the renal excretion of digoxin and may result in increased total urinary output of this glycoside.     

Effect of administration and subsequent cessation of buserelin on cancellous bone of female rats

OBJECTIVE: Low-dose dopamine has been used in critically ill patients to minimize renal dysfunction without sufficient data to support its use. The aim of this study was to determine whether low-dose dopamine improves renal function, and whether dobutamine, a nondopaminergic inotrope, improves renal function. DESIGN: Prospective, randomized, double-blind trial. PATIENTS: Twenty-three patients at risk for renal dysfunction were entered into the study. Five patients were later withdrawn. Study data for the remaining 18 patients were: mean age 55 yrs; mean Acute Physiology and Chronic Health Evaluation (APACHE) II score of 18; mean weight 71 kg). The following conditions were present: mechanical ventilation (n = 17 [inverse-ratio ventilation, n = 6]); inotrope administration (n = 11); sepsis (n = 13); and adult respiratory distress syndrome or multiple organ failure syndrome (n = 9). INTERVENTIONS: The study patients were administered dopamine (200 micrograms/min), dobutamine (175 micrograms/min), and placebo (5% dextrose) over 5 hrs each in a randomized order. Ventilator settings, fluid management, and preexisting inotropic support were not altered during the study. MEASUREMENTS AND MAIN RESULTS: Systemic hemodynamic values and indices of renal function (4-hr urine volume, fractional excretion of sodium, and creatinine clearance) were measured during the last 4 hrs of each infusion. Dopamine produced a diuresis (145 +/- 148 mL/hr) compared with placebo (90 +/- 44 mL/hr; p < .01) without a change in creatinine clearance. Conversely, dobutamine caused a significant increase in creatinine clearance (97 +/- 54 mL/min) compared with placebo (79 +/- 38 mL/min; p < .01), without an increase in urine output. CONCLUSIONS: In stable critically ill patients, dopamine acted primarily as a diuretic and did not improve creatinine clearance. Dobutamine improved creatinine clearance without a significant change in urine output.     

Cross sectional longitudinal study of spot morning urine protein:creatinine ratio, 24 hour urine protein excretion rate, glomerular filtration rate, and end stage renal failure in chronic renal disease in patients without diabetes

OBJECTIVE: To evaluate whether the protein:creatinine ratio in spot morning urine samples is a reliable indicator of 24 hour urinary protein excretion and predicts the rate of decline of glomerular filtration rate and progression to end stage renal failure in non-diabetic patients with chronic nephropathy. DESIGN: Cross sectional correlation between the ratio and urinary protein excretion rate. Univariate and multivariate analysis of baseline predictors, including the ratio and 24 hour urinary protein, of decline in glomerular filtration rate and end stage renal failure in the long term. SETTING: Research centre in Italy. SUBJECTS: 177 non-diabetic outpatients with chronic renal disease screened for participation in the ramipril efficacy in nephropathy study. MAIN OUTCOME MEASURES: Rate of decline in filtration rate evaluated by repeated measurements of unlabelled iohexol plasma clearance and rate of progression to renal failure. RESULTS: Protein:creatinine ratio was significantly correlated with absolute and log transformed 24 hour urinary protein values (P = 0.0001 and P < 0.0001, respectively.) Ratios also had high predictive value for rate of decline of the glomerular filtration rate (univariate P = 0.0003, multivariate P = 0.004) and end stage renal failure (P = 0.002 and P = 0.04). Baseline protein:creatinine ratios and rate of decline of the glomerular filtration rate were also significantly correlated (P < 0.0005). In the lowest third of the protein:creatinine ratio (< 1.7) there was 3% renal failure compared with 21.2% in the highest third (> 2.7) (P < 0.05). CONCLUSIONS: Protein:creatinine ratio in spot morning urine samples is a precise indicator of proteinuria and a reliable predictor of progression of disease in non-diabetic patients with chronic nephropathies and represents a simple and inexpensive procedure in establishing severity of renal disease and prognosis.     

Histamine H1-receptors in HL-60 monocytes are coupled to Gi-proteins and pertussis toxin-insensitive G-proteins and mediate activation of Ca2+ influx without concomitant Ca2+ mobilization from intracellular stores

The responses of renal haemodynamic and natriuretic indices to the oral prostaglandin synthetase inhibitor indomethacin (200 mg), to infused angiotensin II (1 ng min-1 kg-1) and to the combination of the two were studies in placebo-controlled fashion in eight normal male subjects both prior to and following administration of intravenous frusemide (20 mg). As compared with placebo, angiotensin II infusion alone caused significant reductions in absolute rate of sodium excretion, fractional sodium excretion, urine flow rate and effective renal plasma flow (all P < 0.001 vs placebo) but had no effect on glomerular filtration rate. The only change observed in these parameters with indomethacin alone was a small but significant reduction in urine flow rate (P < 0.005 vs placebo). As compared with the effects of angiotensin II alone, indomethacin pre-treatment followed by angiotensin II infusion led to much greater falls in absolute rate of sodium excretion, fractional sodium excretion, urine flow rate and effective renal plasma flow (all P < 0.0001 vs placebo) associated with a significant reduction in glomerular filtration rate (P < 0.0001) not observed with angiotensin II alone. Frusemide administration at the midpoint of each study limb resulted in each case in a prompt 15 to 20 fold increase in natriuresis. The renal haemodynamic and natriuretic effects of angiotensin II, indomethacin and their combination were not qualitatively different from those observed in the pre-frusemide phase. Our findings provide a clear demonstration in man of the important homeostatic role of renal prostaglandins in preserving renal function, particularly glomerular filtration, under conditions of elevated circulating angiotensin II.     

Effect of KATP channel blocker U37883A on renal function in experimental diabetes mellitus in rats

An increase in glomerular filtration rate (GFR) in early diabetes mellitus is considered a risk factor for the development of diabetic nephropathy. Insulin deficiency may increase the activity of ATP-sensitive potassium channels (KATP), which could promote afferent arteriolar vasodilation und thus contribute to glomerular hyperfiltration in early diabetes mellitus. To further elucidate this hypothesis we performed renal clearance experiments in anesthetized rats at 2 and 6 weeks after onset of streptozotocin-induced insulin-treated diabetes mellitus and studied the acute effect of the putative KATP channel blocker 4-morpholinecarboximidine-N-1-adamantyl-N'-cyclohexylhydr ochloride (U37883A) on renal function. In control rats, application of U37883A (1.5 mg/kg i.v. bolus plus 1.5 mg/kg/hr) induced a significant reduction in heart rate, but did not affect or even slightly increased mean arterial blood pressure. Furthermore, U37883A did not significantly affect renal vascular resistance, renal blood flow or GFR, but caused an eukaliuretic diuresis and natriuresis and lowered plasma renin activity. Diabetic rats at both 2 or 6 weeks after streptozotocin exhibited essentially an identical response to U37883A; in particular, RVR and glomerular hyperfiltration remained unchanged. These results show that in both control and diabetic rats, the renal excretory function, renin secretion and pace setting in the heart were sensitiv to U37883A, implying a functional contribution of KATP channel activity. However, in both control and diabetic rats, renal vascular resistance, renal blood flow, or GFR were not altered by U37883A. These results argue against a substantial role for KATP channels in the basal control of renal hemodynamics in both nondiabetic and diabetic rats.     

Isolation of 48 genetic markers appropriate for high throughput genotyping of inbred rat strains by B1 repetitive sequence-representational difference analysis

1. We examined whether zaprinast, a putative cGMP-specific phosphodiesterase inhibitor, affects neural control of renal function in pentobarbital-anaesthetized dogs. 2. Renal nerve stimulation (1 Hz, 1 ms duration) reduced urine flow rate, urinary Na+ excretion (UNaV) and fractional excretion of Na+ (FENa) with little change in either renal blood flow (RBF) or glomerular filtration rate (GFR). 3. Intrarenal arterial infusion of zaprinast (10 and 100 micrograms/kg per min) increased basal urine flow rate, UNaV and FENa but not RBF or GFR. Zaprinast infusion (100 micrograms/kg per min) also increased renal venous plasma cGMP concentration and urinary cGMP excretion. 4. Renal nerve stimulation-induced reductions in UNaV and FENa were attenuated during zaprinast infusion, whereas the reduction in urine flow rate was resistant to zaprinast. 5. Renal nerve stimulation increased the renal venous plasma noradrenaline concentration and renal noradrenaline efflux, which remained unaffected during infusion of zaprinast (100 micrograms/kg per min). 6. The results of the present study suggest that zaprinast induces natriuresis and counteracts adrenergically induced antinatriuresis by acting on renal tubular sites in the dog kidney in vivo.     

Chronic renal failure and nephrolithiasis in a solitary kidney: role of intervention

PURPOSE: We determined the role of intervention and its outcome in patients with a solitary kidney, nephrolithiasis and chronic renal insufficiency, as well as the role of clearance in these patients compared to those with a solitary kidney, nephrolithiasis and normal renal function. MATERIALS AND METHODS: A total of 36 records was evaluable, including 16 from patients with normal (group 1) and 20 from those with abnormal (group 2) renal function. Group 2 was further subdivided into those with mild to moderate (group 2A) and advanced (group 2B) renal failure. Patients with acute renal failure were excluded from the study. Glomerular filtration rate was calculated by the Cockcroft and Gault formula. The reciprocal of serum creatinine was used to determine outcome. RESULTS: Groups 1 and 2 were comparable demographically except for serum creatinine, stone bulk and hospital stay. Of 36 patients 8 with normal renal function and 15 with chronic renal failure underwent percutaneous nephrolitholapaxy, 6 underwent extracorporeal shock wave lithotripsy and 7 underwent open surgery. Total clearance was achieved in 25 of 36 patients (72%). Glomerular filtration rate improved in 24 patients, remained stable in 8 and deteriorated in 4. However, 3 patients had less than 20% deterioration and 1 had significant deterioration in function after intervention. Improvement in glomerular filtration rate after intervention was significantly greater in cases of advanced renal failure. Patients with residual stones did worse than those without residual calculi. Mean hospital stay, deterioration in glomerular filtration rate and major morbidity rate were significantly greater in patients with residual calculi than in those with total clearance. CONCLUSIONS: Intervention should be contemplated in patients with a solitary kidney, stone disease and renal failure as in any other patient with stone disease, with the aim being total clearance. Stone eradication delays deterioration, and decreases the requirement for dialysis and renal replacement.     

Clinicopathology of kidneys from brain-dead patients treated with vasopressin and epinephrine

Studies were made on the biochemical and pathological conditions of kidneys of 20 brain-dead patients who were maintained for 0 to 48 days after brain death by administration of vasopressin and epinephrine. Twenty specimens were obtained by percutaneous biopsy or at autopsy. The biochemical and pathological degrees were compared with those on the day of brain death (day 0). Biochemical tests on day 0 indicated that they showed the diuretic phase of prerenal failure, and then glomerular hyperemia was extensive. Renal function recovered on day 1 and remained almost normal during the 14 day period. Their urine retained high levels of sodium and osmolarity for days 0 to 14, with mild hyponatremia and hypo-osmolarity of the plasma. Tubulointerstitial nephritis gradually became extensive. There was no significant change in the degrees of mesangial widening, mesangial cell proliferation or hyalinosis. Arterial intimal proliferation was gradually extensive after day 3 and glomerular endothelial proliferation was gradually extensive after a week. Brain-dead patients have been mostly reported to develop diabetes insipidus, but our brain-dead patients did not show any manifestation of this disease. We suggest that constant natriuresis and continuing high level of urine osmolarity might have been caused by prerenal renal failure, brain death followed by neurogenic impairment, high level of serum vasopressin, or interstitial nephritis.     

Effect of anaesthesia with nitrous oxide in oxygen and fentanyl on renal function in the artificially ventilated dog

The effect on renal function of a large dose (25 micrograms kg-1) of fentanyl was investigated in 10 labrador dogs. The animals were anaesthetized with nitrous oxide in oxygen and a small supplement of fentanyl 0.4 microgram min-1 throughout the experiment, and muscular relaxation was provided by alcuronium, pulmonary ventilation being controlled. In the initial phase of each experiment, estimated renal plasma flow, glomerular filtration rate, urine volume, mean arterial pressure and renal vascular resistance were measured at 30-min intervals, three sets of samples being taken. Then the large dose of fentanyl was given over a 10-min period and the measurements were repeated at 30-min intervals for 90 min. Changes in renal function lasted for about 90 min; there was a significant decrease in estimated renal plasma flow (P less than 0.01), glomerular filtration rate (P less than 0.001), urine volume (P less than 0.01) and mean arterial pressure (P less than 0.001) together with an increase in renal vascular resistance (0.05 greater than P greater than 0.02). These changes were accompanied by bradycardia, but were still present when atropine was given.     

Effect, on renal function, of a product rich in polyunsaturated fatty acids: results obtained in subjects with chronic renal failure caused by nephroangiosclerosis

Subjects with renal chronic failure were studied. Four patients were treated with 2,5 mg/Kg of phosphatidylcholine, a drug with an high content of polyunsatured fatty acids. The drug's effects, studied during three successive 30 min. Clearance periods, were the same as in healthy subjects, i.e.: a statistically significant increase of: urine flow, renal blood flow, glomerular filtration rate and sodium excretion. In other 6 patients, administration of i.v. lysine acetylsalicylate (10,5 mg/Kg) caused a decrease of the parameters under study, that were increasing for a previous dose of phosphatidylcholine and made ineffective another administration of this drug. If the thesis is assumed that in normal subjects phenomena may be referred to the local synthesis of PG, then the authors believe that the potential synthesis capacity of these substances is not compromised in chronic renal failure.