PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 2485447

Postnatal development of renal function.

P A Jose·R D Fildes
View original source ↗Export metadata ↓

Abstract

Renal function in the newborn is both qualitatively and quantitatively different from older infants, children and adults. Moreover, gestational age is of great importance in the interpretation of renal functional differences. These differences in renal function should not be viewed as solely immaturity per se but rather as functional adaptations to the needs of growth and development in many instances. Although the neonatal kidney is operating at a level appropriate for a given age, the decreased functional reserve makes it more vulnerable to stressful conditions. However, the low GFR and some of the decreased transport properties may actually be of benefit to the neonate. With respect to medications, one benefit of these neonatal differences appears to be less nephrotoxicity for certain drugs in the newborn compared with the adult.

Explore related subjects

Acid-Base EquilibriumAgingAnimalsCalciumEmbryonic and Fetal DevelopmentFemaleHormonesHumansKidneyKidney GlomerulusPhosphorusPotassiumPregnancyReference ValuesRegional Blood FlowRenal CirculationSodiumJournal ArticleReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P A Jose, R D Fildes. 1988. Postnatal development of renal function.. https://pubmed.ncbi.nlm.nih.gov/2485447/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

Ionoregulatory disruption as the acute toxic mechanism for lead in the rainbow trout (Oncorhynchus mykiss).

The mechanism for acute toxicity of lead (Pb) in rainbow trout (Oncorhynchus mykiss) was investigated at Pb concentrations close to the 96 h LC50 of 1.0 mg dissolved Pb l(-1) (0.8-1.4, 95% C.I.) determined in dechlorinated Hamilton city tap water (from Lake Ontario, hardness=140 mg l(-1) CaCO(3)). Tissue Pb accumulation associated with death was highest in the gill, followed by kidney and liver. Significant ionoregulatory impacts were observed in adult rainbow trout (200-300 g) fitted with indwelling dorsal aortic catheters and exposed to 1.1+/-0.04 mg dissolved Pb l(-1). Decreased plasma [Ca(2+)], [Na(+)] and [Cl(-)] occurred after 48 h of exposure through to 120 h, with increases in plasma [Mg(2+)], ammonia, and cortisol. No marked changes in PaO(2), PaCO(2), pH, glucose, or hematological parameters were evident. Branchial Na(+)/K(+) ATPase activity in juvenile trout exposed to concentrations close to the 96 h LC50 was inhibited by approximately 40% after 48 h of Pb exposure. Calcium ion flux measurements using 45Ca as a radiotracer showed 65% inhibition of Ca(2+) influx after 0, 12, 24 or 48 h exposure to the 96 h LC50 concentration of Pb. There was also significant inhibition (40-50%) of both Na(+) and Cl(-) uptake, measured with 22Na and 36Cl simultaneously. We conclude that the mechanism of acute toxicity for Pb in rainbow trout occurs by ionoregulatory disruption rather than respiratory or acid/base distress at Pb concentrations close to the 96 h LC50 in moderately hard water.

Acid-Base Equilibrium↗
PubMed2003

Targeted O2 delivery by low-P50 hemoglobin: a new basis for O2 therapeutics.

To assess O2 delivery to tissue by a new surface-modified, polyethylene glycol-conjugated human hemoglobin [MP4; Po2 at 50% saturation of hemoglobin (P50); 5.4 mmHg], we studied microcirculatory hemodynamics and O2 release in golden Syrian hamsters hemodiluted with MP4 or polymerized bovine hemoglobin (PolyBvHb; P50 54.2 mmHg). Comparisons were made with the animals' hemodiluted blood with a non-O2 carrying plasma expander with similar solution properties (Dextran-70). Systemic hemodynamics (arterial blood pressure and heart rate) and acid-base parameters were not correlated with microhemodynamics (arteriolar and venular diameter, red blood cell velocity, and flow). Microscopic measurements of Po2 and the O2 equilibrium curves permitted analysis of O2 release in precapillary and capillary vessels by red blood cells and plasma hemoglobin separately. No significant differences between the groups of animals with respect to arteriolar diameter, flow, or flow velocity were observed, but the functional capillary density was significantly higher in the MP4-treated animals (67%) compared with PolyBvHb-treated animals (37%; P < 0.05) or dextran-treated animals (53%). In the PolyBvHb-treated animals, predominant O2 release (both red blood cells and plasma hemoglobin) occurred in precapillary vessels, whereas in MP4 animals most of the O2 was released from both red blood cells and plasma hemoglobin in capillaries. Base excess correlated directly with capillary O2 release but not systemic O2 content or total O2 release. Higher O2 extraction of both red blood cell and plasma hemoglobin in capillaries represents a new mechanism of action of cell-free hemoglobin. High O2 affinity appears to be an important property for cell-free hemoglobin solutions.

Acid-Base Equilibrium↗