Journal article
Ontogenic changes in renal response to alpha 1-adrenoceptor stimulation in sheep
American journal of physiology. Regulatory, integrative and comparative physiology, Vol.267(4), pp.R990-R998
10/01/1994
DOI: 10.1152/ajpregu.1994.267.4.R990
PMID: 7943440
Abstract
The present study was designed to examine the effect of direct intrarenal infusion of the alpha 1-adrenoceptor agonist, phenylephrine, on urinary flow rate (UFR) and on renal Na and Cl excretion in conscious and chronically instrumented fetal (128-133 days gestation, term 145 days), newborn (6-12 days), and adult sheep. Five different renal concentrations of phenylephrine, varying from 5 +/- 1 to 72 +/- 2 ng/ml, were studied. Low renal phenylephrine concentration (< or = 12 +/- 1 ng/ml) induced a significant renal vasoconstrictor response in fetuses but not in newborn and adult sheep. The effects of intrarenal phenylephrine infusion on UFR and fractional excretion of Na (FENa) was greater (P < 0.05) in newborn lambs than in fetal and adult sheep. At a renal concentration of phenylephrine between 9 +/- 1 and 12 +/- 1 ng/ml, the percent decrease in UFR was greater (P < 0.05) in newborn lambs (-19.1 +/- 4.7%) than in fetal (9.8 +/- 8.9%) and adult sheep (-3.3 +/- 3.9). The percent decrease in FENa at renal concentration of phenylephrine between 18 +/- 1 and 24 +/- 1 ng/ml was also significantly (P < 0.05) larger in newborn lambs (-20.2 +/- 2.8%) than in fetal (-8.0 +/- 3.1%) and adult sheep (-11.2 +/- 2.6%). In summary, the present results indicate that the fetal kidney has a limited ability to increase sodium reabsorption in response to stimulation of alpha-adrenoceptors and that the effect of renal alpha-adrenoceptor stimulation on urinary volume and urinary sodium excretion increases during the newborn period.
Details
- Title: Subtitle
- Ontogenic changes in renal response to alpha 1-adrenoceptor stimulation in sheep
- Creators
- Edward N Guillery - Department of Pediatrics and Cardiovascular Center, University of IowaCollege of Medicine, Iowa City 52242Jeffrey L Segar - Department of Pediatrics and Cardiovascular Center, University of IowaCollege of Medicine, Iowa City 52242David C Merrill - Department of Pediatrics and Cardiovascular Center, University of IowaCollege of Medicine, Iowa City 52242Kenneth T Nakamura - Department of Pediatrics and Cardiovascular Center, University of IowaCollege of Medicine, Iowa City 52242Pedro A Jose - Department of Pediatrics and Cardiovascular Center, University of IowaCollege of Medicine, Iowa City 52242Jean E Robillard - Department of Pediatrics and Cardiovascular Center, University of IowaCollege of Medicine, Iowa City 52242
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Regulatory, integrative and comparative physiology, Vol.267(4), pp.R990-R998
- DOI
- 10.1152/ajpregu.1994.267.4.R990
- PMID
- 7943440
- ISSN
- 0363-6119
- eISSN
- 1522-1490
- Language
- English
- Date published
- 10/01/1994
- Academic Unit
- Molecular Physiology and Biophysics; Nephrology, Dialysis and Transplantation; Stead Family Department of Pediatrics; Medicine Administration
- Record Identifier
- 9984025325502771
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