Urinary prostaglandins, vasopressin, and kallikrein excretion in healthy children from birth to adolescence

Godard, Claude; Vallotton, Michel B.; Favre, L.

doi:10.1016/s0022-3476(82)80508-8

Cited by 32 publications

(12 citation statements)

References 19 publications

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“…The urinary excretion of kallikrein, as a measure of the renal KKS activity, has been shown to exhibit a developmental increase both in humans [5,6] and in animal models [7]. Renal kallikrein gene transcription and activity was also found to be up-regulated in newborn rats [8].…”

Section: Introductionmentioning

confidence: 99%

Endogenous Bradykinin Regulates Renal Function in the Newborn Rabbit

Tóth-Heyn

Guignard²

1998

Neonatology

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The developmental changes in the activity of the renal kallikrein-kinin system (KKS) are related to the hemodynamic changes occurring in the neonatal kidney. In order to clarify the functional importance of the renal KKS in the developing kidney, the effect of the bradykinin B2 receptor antagonist HOE-140 was investigated in newborn rabbits. Effective blockade of bradykinin effect by HOE-140 was demonstrated in 10 rabbits. In 10 additional animals the subcutaneous injection of 300 µg/kg HOE-140 resulted in an increase in renal vascular resistance with a consequent decrease in renal blood flow. Glomerular filtration rate did not change significantly, while the filtration fraction rose, indicating preferential efferent arteriolar constriction. Urine flow rate increased as well as the fractional excretion of potassium. No change in sodium excretion was observed. The present data suggest a regulatory role for the renal KKS in the immature kidney under basal conditions. By inducing predominant efferent arteriolar vasodilation, the KKS appears to play a key role in regulating the neonatal glomerular microcirculation. This is in sharp contrast with the mature kidney, where the KKS predominantly acts on tubular function as a diuretic-natriuretic factor.

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Section: Introductionmentioning

confidence: 99%

Endogenous Bradykinin Regulates Renal Function in the Newborn Rabbit

Tóth-Heyn

Guignard²

1998

Neonatology

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“…The renal kallikrein-kinin, the renin-angiotensin-aldosterone and the renal eicosanoids systems are the three major classes of vasoactive hormones which at present are thought to play a role in the regulation of renal function in the adult [1,2], In recent years increased attention has been given to study these vasoactive substances in the de veloping kidney [3] and, although it has been established that the activity of the reninangiotensin-aldosterone system and the uri nary output of renal prostaglandins are markedly elevated during the neonatal age [4,5], little is known about the renal kalli krein-kinin system on the very early neona tal period in humans [6][7][8]. The present work was designed to study the excretion of renal kallikrein at birth in newborns of dif ferent gestational ages, and correlate its ex cretion with conventional parameters of re nal function.…”

Section: Introductionmentioning

confidence: 99%

Kallikrein Excretion: Relationship with Maturation and Renal Function in Human Neonates at Different Gestational Ages

et al. 1987

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Kallikrein excretion and renal function were studied on 37 one-day-old newborn infants (14 fullterm and 23 preterm infants). Preterm infants excreted less kallikrein (p < 0.001), had lower creatinine clearance (p < 0.02) and urinary osmolality (p < 0.01). They had higher values on urinary volume (p < 0.001), FE_Na (p < 0.001), FE_K (p < 0.02), and free water clearance (p < 0.01) than fullterm infants. The excretion of kallikrein correlated directly with gestational age (p < 0.01) and body weight (p < 0.01). No correlations were found with FE_Na, urinary volume, FE_K or free water clearance. The values of kallikrein excretion were very low when compared with a young adult population. As kallikrein is synthesized in the distal nephron we advance as an hypothesis that the low levels of kallikrein excretion observed in newborns could be a reflection of immature distal tubular mass, and to the relative unresponsiveness of the distal nephron to hormones known to stimulate renal kallikrein such as aldosterone and antidiuretic hormone.

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“…In human infants, results from studies measuring urinary PGE 2 have been inconsistent. Some studies have shown lower urinary prostaglandins in infants (41,106). Conversely, Joppich et al (57) showed that the levels of urinary PGE 2 were higher in preterm than in full-term infants.…”

Section: Role Of Prostaglandinsmentioning

confidence: 98%

Development of water transport in the collecting duct

Bonilla–Félix¹

2004

American Journal of Physiology-Renal Physiology

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Bonilla-Felix, Melvin. Development of water transport in the collecting duct. Am J Physiol Renal Physiol 287: F1093-F1101, 2004; doi:10.1152/ajprenal.00119. 2004.-The ability of the immature kidney to concentrate urine is lower than in adults. This can lead to severe water and electrolyte disorders, especially in premature babies. Resistance to AVP and lower tonicity of the medullary interstitium seem to be the major factors limiting urine concentration in newborns. AVP-stimulated cAMP generation is impaired. This is the result of inhibition of the production by PGE 2 acting through EP3 receptors and increased degradation by phosphodiesterase IV. The expression of aquaporin-2 (AQP2) in the immature kidney is low; however, under conditions of water deprivation and after stimulation with DDAVP, it rises to adult levels. The expression of AQP3 and AQP4 is intact at birth and does not seem to contribute to the hyporesponsiveness to AVP. Low sodium transport by thick ascending loops of Henle, immaturity of the medullary architecture, and adaptations in the transport of urea contribute to the lower tonicity of the medullary interstitium. This paper reviews the alterations in the AVP signal transduction pathway in the immature kidney. immature kidney; arginine vasopressin; aquaporins; prostaglandins WATER CONSERVATION IS ONE of the most important functions of the kidney. Before birth, the ability of the organism to conserve water is not critical as the placenta controls fluid balance in the fetus. The event of birth prompts abrupt changes in the infant's environment, rendering the newborn responsible for keeping fluid and electrolyte homeostasis. Although nephrogenesis in full-term human infants is completed before birth, tubular development continues during the first few years of life. This limits the ability of the immature kidney to reabsorb water, which usually reaches adult levels by 1 yr of age. As early as 1941, McCance and Young (72) observed that the urine of a group of infants from 7 to 14 days of age was always hypotonic (72). Studies in young rats (first 3 wk of life) subjected to 8 h of dehydration showed that the maximal osmolality achieved was close to 1,000 mosmol/kgH 2 O, which was only ϳ50% of the levels reached by adult rats subjected to the same stimulus (32).In infants, total body water is higher at birth (45, 91). Under normal physiological conditions, the kidneys have to excrete this load of water during the first week of life (91). Therefore, maximal abilities to concentrate urine are not considered necessary at birth. However, this limitation places premature infants, who frequently have other associated medical problems, at greater risk for serious imbalances in water and electrolyte homeostasis (20,101,104). For years, scientists have tried to identify the factors mediating the limitation in urine concentration observed in the immature kidney. The major aim of this paper is to review the progress in investigating the development of water transport in the collecting duct (CD) and its respons...

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Urinary prostaglandins, vasopressin, and kallikrein excretion in healthy children from birth to adolescence

Cited by 32 publications

References 19 publications

Endogenous Bradykinin Regulates Renal Function in the Newborn Rabbit

Endogenous Bradykinin Regulates Renal Function in the Newborn Rabbit

Kallikrein Excretion: Relationship with Maturation and Renal Function in Human Neonates at Different Gestational Ages

Development of water transport in the collecting duct

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