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T Tulassay

Publications and source records attributed to T Tulassay.

At least 127 records · Page 7Linked to original sources
PubMed1987

Atrial natriuretic peptide and other vasoactive hormones during treatment of severe diabetic ketoacidosis in children.

Plasma concentrations of atrial natriuretic peptide (ANP), arginine vasopressin (AVP), renin activity (PRA), aldosterone, norepinephrine, and cortisol, and renal functions were investigated in nine children with diabetic ketoacidosis. Before therapy, blood glucose concentration was 608.4 +/- 142.2 mg/dL and base excess -21 +/- 1.9 mmol/L. The calculated volume depletion was 2505 +/- 1005 mL/1.73 m2. At the onset of the study, the plasma concentration of ANP (5.3 +/- 1.2 fmol/L) was low, and concentrations of AVP (159 +/- 44 pg/mL), PRA (59 +/- 19 ng angiotensin l/mL/hr), aldosterone (114 +/- 11 ng/dL), norepinephrine (430 +/- 67 pg/mL), and cortisol (33 +/- 2.1 micrograms/dL) were markedly elevated. Fluid replacement raised plasma ANP concentration, which reached physiologic levels on the first day of therapy. PRA, aldosterone, norepinephrine, and cortisol also normalized during the first 24 hours of therapy, whereas AVP remained above the physiologic range at 20.4 +/- 6.8 pg/mL on the third day. Our data indicate that in diabetic ketoacidosis, volume depletion, enhanced sodium excretion, and hyponatremia activated vasoconstrictor and sodium-retaining hormone systems and that secretion of the natriuretic and vasodilator hormone ANP is suppressed. All of these hormonal alterations seem directed at maintaining adequate fluid volume and sodium homeostasis.

Adolescent↗
PubMed1987

Atrial natriuretic peptide and other vasoactive hormones in nephrotic syndrome.

Plasma levels of atrial natriuretic peptide (ANP), arginine vasopressin (AVP), renin activity (PRA), aldosterone (PA), catecholamines and urinary prostaglandins (PG), as well as renal function were measured in children in the edematous state of the nephrotic syndrome before and after infusion of human serum albumin. Before albumin infusion, plasma levels of AVP, PRA, PA and noradrenaline (NA) and urinary excretion of PGE2, PGE-Met, PGF2 alpha were elevated. The mean value of plasma ANP was in the normal range. Albumin infusion produced a 36% increase in the calculated plasma volume. It was associated with a fivefold rise in the plasma level of ANP (31.6 +/- 22.6 vs. 151.4 +/- 52 fmol/ml mean, SD), and a significant fall in the levels of PRA, AVP, PA, and NA. Similarly, urinary concentration of PGE2, PGE-Met and PGF2 alpha fell. Urine flow, GFR, UNaV, FENa, and COsm increased significantly, while CH2O remained unchanged. The diuresis, natriuresis and GFR correlated with the level of plasma ANP, while urinary sodium excretion did not correlate with PA or NA levels. These findings suggest that ANP plays an important role in albumin induced natriuresis in children with nephrotic syndrome.

Adolescent↗
PubMed1987

Influence of dopamine on atrial natriuretic peptide level in premature infants.

The role of dopamine (DA) in the activation and/or release of atrial natriuretic peptide (ANP) was investigated in 11 premature infants during the early postnatal period. Mean plasma concentration of ANP and free DA level before DA infusion was 252.6 +/- 210 fmol/ml, and 0.4 +/- 0.2 ng/ml, respectively. DA infusion in a dose of 2 micrograms/kg/min caused a rise in plasma free DA level to 59.7 +/- 21.5 ng/ml and a significant increase in GFR, diuresis, sodium excretion and fractional sodium excretion. The plasma concentration of ANP, however, remained unchanged (252.6 +/- 210.0 vs. 213 +/- 143.0 fmol/ml). Thus, our data failed to demonstrate a stimulatory effect of DA on ANP release in premature infants. The role of the high plasma concentration of ANP in preterm neonates immediately after birth has to be clarified.

Atrial Natriuretic Factor↗
PubMed1987

Atrial natriuretic peptide and extracellular volume contraction after birth.

Plasma concentrations of atrial natriuretic peptide (ANP) were measured in full-term newborns immediately after birth and on the 3rd, 5th, 7th and 10th day of life. The ANP concentrations were within the normal range in the first hours of life. Plasma concentrations of ANP had increased significantly on the 3rd and 5th day of life, while body weight decreased continuously. After the 5th day of life ANP concentration decreased continuously reaching its minimum on the 10th day whereas body weight increased. The mechanism behind ANP release shortly after birth is not known. The increase in ANP concentration in plasma may however induce changes in body fluid compartments shortly after birth which would result in physiological weight loss.

Age Factors↗
PubMed1987

Atrial natriuretic peptide in infants and children.

Atrial natriuretic peptide (ANP) was measured in the plasma of 192 normal infants and children aged 1 day to 18 years. Plasma ANP was high during postnatal adaptation, particularly in premature infants. In 96 infants and children aged 4 months to 18 years, plasma ANP was similar to values obtained in 7 healthy adult volunteers (23.9 +/- 11.9 vs. 25.7 +/- 4.6 fmol/ml). There was no significant relationship between ANP and age. ANP is elevated about twofold in full-term neonates being 3-4 days of age, and returned to normal thereafter. It is concluded that ANP is raised during the postnatal adaptation. This hormone is possibly involved in the postnatal volume contraction and may antagonize vasoconstrictor hormones that are elevated during the postnatal period.

Adolescent↗
PubMed1987

Hormonal regulation of water metabolism in children with nephrotic syndrome.

The roles of the antidiuretic hormone arginine-vasopressin (AVP), atrial natriuretic peptide (ANP), renin, aldosterone and catecholamines in the pathogenesis of impaired water excretion were studied in edematous children with nephrotic syndrome. Compared to non-proteinuric children with nephrotic syndrome in remission, edematous children during relapse had lower serum concentrations of sodium and chloride with lower plasma osmolality, but had higher hematocrit values (P less than 0.05, each). Plasma concentration of AVP was higher in edematous children (P less than 0.01). Compared to healthy, normal children, edematous nephrotic children had higher plasma concentrations of AVP, aldosterone, renin, noradrenaline, and adrenaline (P less than 0.01, each), but had similar levels of plasma ANP. Head out water immersion and infusion of 5 ml/kg 20% human serum albumin solution, both procedures known to increase central blood volume, resulted in a reduction of elevated hormone concentrations to near-normal levels and caused a rise in sodium and water excretion. Following albumin infusion, mean ANP rose fivefold, and plasma concentrations of this hormone correlated positively with urine flow (r = 0.64, N = 18, P less than 0.01) and with sodium excretion (r = 0.62, N = 18, P less than 0.01). It is concluded that AVP, renin, aldosterone and catecholamines are stimulated in edematous children with nephrotic syndrome by reduction in effective circulatory blood volume. Central blood volume expansion induced either by water immersion or by infusion of concentrated albumin solution is able to correct elevated hormone levels and to induce salt and water excretion. Plasma ANP appears to trigger the diuretic and natriuretic effects of central volume expansion.

Aldosterone↗
PubMed1987

Effect of low-dose dopamine on kidney function and vasoactive hormones in pediatric patients with advanced renal failure.

Dopamine (DA) was infused in a dose of 2 micrograms/kg/min in 12 children and adolescents with chronic renal failure to test the vasodilatory reserve capacity of the kidney. Mean basal GFR and ERPF were 17.8 and 93.1 ml/min/1.73 m2, respectively. DA infusion had no significant influence on GFR but effective renal plasma flow (ERPF) increased by 14% (p less than 0.05). After DA, GFR did not correlate with ERPF. There was a significant increase in urinary sodium excretion (+22%). Sodium excretion correlated with osmotic clearance and urine flow rate with free water clearance. Plasma prolactin concentration was decreased (p less than 0.01), whereas noradrenaline, adrenaline and free dopamine increased significantly after DA. Plasma renin activity, aldosterone, arginine vasopressin and atrial natriuretic peptide levels remained unchanged. The data indicate that in pediatric patients with advanced renal failure DA fails to increase filtration capacity, whereas effective renal plasma flow and sodium excretion are stimulated. It is speculated that in this situation preglomerular and tubular renal functions regulated by dopamine receptors are better conserved than those affecting glomerular microcirculation.

Adolescent↗
PubMed1986

Diuretic and hormonal responses to head-out water immersion in nephrotic syndrome.

The diuretic and natriuretic response to water immersion, which is known to increase effective central blood volume, was studied in eight edematous children with nephrotic syndrome. The rise in central blood volume was indicated by a decrease in hematocrit from preimmersion median of 40.2% to 38.6% during water immersion (P less than 0.05, Friedman test). Similarly, serum protein concentration fell from 36.7 gm/L to 33.5 gm/L (P less than 0.05). Water immersion induced diuresis from a preimmersion median of 0.33 ml/min/1.73 m2 to 1.52 ml/min/1.73 m2 (P less than 0.05). Osmolar clearance rose, as did sodium and potassium excretion. Urine osmolality fell during water immersion (P less than 0.05). Serum sodium concentration and plasma osmolality did not change. Plasma arginine vasopressin values fell from 11.1 pg/ml to 3.0 pg/ml (P less than 0.05), as did renin activity (8.5 ng to 5.2 ng angiotensin l/ml/hr, P less than 0.01), aldosterone (18.0 ng/dl to 10.1 ng/dl), and norepinephrine (344 pg/ml to 213 pg/ml, P less than 0.05). Water immersion produces a potent natriuretic and diuretic response in children with nephrotic syndrome.

Adolescent↗
PubMed1986

Role of atrial natriuretic peptide in sodium homeostasis in premature infants.

To examine the possible involvement of atrial natriuretic peptide (ANP) in sodium homeostasis in premature infants, two groups of low birth weight infants with different dietary sodium regimens were studied. Sodium balance and plasma concentration of ANP were measured at weekly intervals for 5 weeks. At 1 week of age the study was started by dividing infants into two groups, group 1 with low and group 2 with increased sodium intake. Mean plasma concentrations of ANP were 47.7 +/- 7.6 and 51.4 +/- 9.5 fmol/ml, respectively. A steady decrease in plasma ANP concentration to 18.8 +/- 2.9 fmol/ml was observed in infants with sodium intake 1.5 mmol/kg/d (group 1), which was related to the decrease in serum sodium concentration in this group. In contrast, supplementation with NaCl 4.6 mmol/kg/d (group 2) was associated with a 30% increase in plasma ANP concentration, significantly different (P less than 0.025) from that in infants not given supplement, and was also higher than the values in full-term neonates. Our data suggest that altered sodium homeostasis induces regulatory changes in plasma ANP levels. ANP may provide a sensitive and important hormonal system for the control of sodium balance, even in premature neonates.

Atrial Natriuretic Factor↗
PubMed1986

Alterations of urinary carbon dioxide tension, electrolyte handling and low molecular weight protein excretion in acute pyelonephritis.

Renal tubular function tests were performed in 45 children suffering from upper and lower urinary tract infections. Determinations were made of the urinary carbon dioxide tension in maximally alkaline urine as an index of distal tubular H+-ion secretion, of urinary protein excretion, and of urinary sodium and phosphate handling. Urinary PCO2 was low (2.7 +/- 13.9 mmHg) in acute pyelonephritis compared to values in healthy children (52 +/- 32 mmHg) or those with cystitis (48 +/- 34 mmHg). At the onset of pyelonephritis an elevated fractional excretion of sodium (1.38 +/- 0.38 vs. 0.50 +/- 0.20%) and decreased phosphate reabsorption (69.2 +/- 7.1 vs. 90.4 +/- 4.9%) were also observed. Significantly elevated urinary low molecular weight protein excretion was also found in pyelonephritis. These data indicate the existence of proximal and distal tubular dysfunction at the onset of acute bacterial pyelonephritis.

Acute Disease↗
PubMed1986

Acute oliguria in preterm infants with hyaline membrane disease: interaction of dopamine and furosemide.

Ten premature infants with hyaline membrane disease and with acute oliguria were treated with furosemide or furosemide and dopamine. Furosemide alone did not increase diuresis. Furosemide when combined with dopamine, however, caused significant increases in urine output, sodium excretion, fractional sodium excretion and creatinine clearance. These data suggest that the increase in the sodium excretion was due not only to a reduction in the tubular sodium reabsorption but also to an increase in the glomerular filtration rate. Since in premature neonates the creatinine clearance is not a very precise index of the glomerular filtration rate, the extent of contribution of the increase in the glomerular filtration rate to the enhanced sodium excretion cannot be determined. Despite the increase in the sodium excretion, the serum sodium concentration did not fall significantly. We conclude that the combined treatment with dopamine and furosemide is useful for treating furosemide-resistant, severe functional renal failure in preterm infants with hyaline membrane disease.

Anuria↗
PubMed1986

Atrial natriuretic peptide and volume changes in children.

The effect of volume changes on the plasma concentration of atrial natriuretic peptide (ANP) was investigated. In children with chronic renal failure predialysis plasma ANP was higher as compared to normal children and decreased significantly during hemodialysis. The decrease in plasma ANP correlated with body weight reduction. On the other hand, increase in plasma volume by infusion of albumin in children with nephrotic syndrome caused significant rise in plasma ANP and an increased natriuresis. Our data demonstrate that an expanded extracellular fluid volume and/or plasma volume appears to be a major stimulus for the release in ANP in children.

Adolescent↗
PubMed1986

[Atrial natriuretic peptide. New aspects in the regulation of blood volume and electrolyte homeostasis].

Atrial natriuretic peptide (ANP) is a newly discovered hormone released from cardiac atrial myocytes into the circulation. Secretion of the hormone is triggered by atrial distension and volume overload. ANP consist of 28 aminoacids. The hormone induces natriuresis, diuresis and increases glomerular filtration rate. Moreover, it dilates vascular smooth muscle and opposes the effects of several vasoactive hormones. Thus ANP plays an important role in the regulation of body fluids and electrolyte homeostasis.

Aldosterone↗
PubMed1985

Atrial natriuretic peptide in plasma of volume-overloaded children with chronic renal failure.

The effect of volume changes on the plasma concentration of atrial natriuretic peptide (ANP) in children with chronic renal failure was investigated by the use of a specific and sensitive radioimmunoassay. Predialysis plasma ANP was significantly higher in children with end-stage renal disease than in healthy children and children with advanced renal failure without evidence of volume expansion. During haemodialysis plasma ANP decreased significantly and plasma renin activity rose slightly, whereas plasma arginine vasopressin and aldosterone did not change. Plasma ANP correlated positively with volume status (body weight gain during the interval between two haemodialysis sessions). An expanded extracellular fluid volume thus seems to be a major stimulus for the rise in ANP in children with end-stage renal disease. The findings suggest that ANP may be important in volume homoeostasis.

Adolescent↗
PubMed1985

The effect of dopamine administration on the activity of the renin-angiotensin-aldosterone system in sick preterm infants.

Nine premature infants with birth weight of 1150 to 2500 g and gestational age of 28 to 35 weeks were given dopamine in a dose of 2-4 micrograms/kg/min to treat cardiopulmonary distress. In addition to monitoring of blood gases, blood pressure, acid-base balance, urine flow and urinary sodium excretion, plasma renin activity (PRA) and plasma aldosterone concentration (PA) was also determined prior to and during dopamine therapy. The dopamine-induced increase in urine flow and urinary sodium excretion was associated with a significant increase of PRA from 18.2 +/- 5.1 ng/ml/h to 33.0 +/- 5.6 ng/ml/h (P less than 0.025), while PA and blood pressure remained unaltered by dopamine administration. It is suggested that the angiotensin II-stimulated aldosterone production is overridden by the inhibitory effect of dopamine.

Aldosterone↗