Journal article
Ontogeny of alpha-adrenoceptor responses in renal vascular bed of sheep
American journal of physiology. Regulatory, integrative and comparative physiology, Vol.254(2), pp.R277-R283
02/01/1988
DOI: 10.1152/ajpregu.1988.254.2.R277
PMID: 2830795
Abstract
The renal hemodynamic response to renal arterial infusions of guanabenz (alpha 2-adrenoceptor agonist) and phenylephrine (alpha 1-adrenoceptor agonist) were compared in conscious and chronically instrumented fetal (132-140 days gestation; term 145 days), newborn (6-15 days postnatal), and nonpregnant adult sheep. Phenylephrine produced similar dose-related decreases in renal blood flow velocity in all three groups at low concentrations (less than 1.8 X 10(-7) M) of drug in renal blood, whereas at the highest concentration adults demonstrated the most vasoconstriction and newborns the least (P less than 0.05 ANOVA). Responses to phenylephrine infusion during renal alpha 1-adrenoceptor blockade with prazosin were completely inhibited. Guanabenz produced greater renal vasoconstriction in adult sheep (P less than 0.05 ANOVA) at all concentrations (0.6 X 10(-6) to 8 X 10(-6) M) when compared with fetal and newborn sheep. Guanabenz-mediated vasoconstriction was not affected by alpha 1-adrenoceptor blockade with prazosin but was completely inhibited by the addition of an alpha 2-adrenoceptor antagonist idazoxan. Results of the present study demonstrate that renal vasoconstriction is mediated by both alpha 1- and alpha 2-adrenoceptors in fetal, newborn, and adult sheep. Moreover, these results suggest that renal alpha 1- and alpha 2-adrenoceptor-mediated vasoconstrictor responses mature at different rates.
Details
- Title: Subtitle
- Ontogeny of alpha-adrenoceptor responses in renal vascular bed of sheep
- Creators
- G. P Matherne - Department of Pediatrics, University of Iowa College of Medicine, IowaCity 52242K. T Nakamura - Department of Pediatrics, University of Iowa College of Medicine, IowaCity 52242J. E Robillard - Department of Pediatrics, University of Iowa College of Medicine, IowaCity 52242
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Regulatory, integrative and comparative physiology, Vol.254(2), pp.R277-R283
- DOI
- 10.1152/ajpregu.1988.254.2.R277
- PMID
- 2830795
- ISSN
- 0363-6119
- eISSN
- 1522-1490
- Language
- English
- Date published
- 02/01/1988
- Academic Unit
- Molecular Physiology and Biophysics; Nephrology, Dialysis and Transplantation; Stead Family Department of Pediatrics; Medicine Administration
- Record Identifier
- 9984025558102771
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