Journal article
Regional variation of postjunctional α-adrenoceptor responses in the developing renal vascular bed of sheep
Pediatric research, Vol.25(5), pp.461-465
1989
DOI: 10.1203/00006450-198905000-00007
PMID: 2541395
Abstract
Postjunctional alpha 1- and alpha 2-adrenoceptor vasoconstrictor responses were evaluated in isolated segments of main renal artery, segmental renal artery, and renal vein from fetal (130-138 d of gestation; term 145 d), newborn (3-15 d age), and nonpregnant adult sheep. Vascular rings were mounted at their optimal resting tension and responses to phenylephrine (alpha 1-adrenoceptor agonist) and guanabenz and UK14304 (both alpha 2-adrenoceptor agonists) were determined. Optimal resting tension increases with development in the main renal artery, segmental renal artery, and renal vein of sheep. Arterial vessels develop more isometric tension to alpha 1-adrenoceptor stimulation than to alpha 2-adrenoceptor stimulation, whereas venous segments develop similar isometric tension to alpha 1- and alpha 2-adrenoceptor stimulation. The segmental renal artery develops more isometric tension to alpha 2-adrenoceptor stimulation than the main renal artery. No large developmental differences exist among vessels in the sensitivity (concentration required for half maximal response, ED50) to alpha-adrenoceptor stimulation except for the renal vein with alpha 2-adrenoceptor stimulation. Maximum isometric tension corrected for vessel cross-sectional area decreases with age for all vessels with both alpha 1- and alpha 2-adrenoceptor stimulation. These findings may reflect developmental differences in receptor number and affinity or differences in vascular smooth muscle function. In addition, these data suggest that whereas both alpha 1- and alpha 2-adrenoceptors mediate vasoconstriction in the renal circulation, they may do so at different sites.
Details
- Title: Subtitle
- Regional variation of postjunctional α-adrenoceptor responses in the developing renal vascular bed of sheep
- Creators
- G Paul Matherne - Univ. Iowa coll. medicine, dep. pediatrics, Iowa City IA 52242, United StatesKenneth T Nakamura - Univ. Iowa coll. medicine, dep. pediatrics, Iowa City IA 52242, United StatesBeth M ALDEN - Univ. Iowa coll. medicine, dep. pediatrics, Iowa City IA 52242, United StatesNancy J Rusch - Univ. Iowa coll. medicine, dep. pediatrics, Iowa City IA 52242, United StatesJean E Robillard - Univ. Iowa coll. medicine, dep. pediatrics, Iowa City IA 52242, United States
- Resource Type
- Journal article
- Publication Details
- Pediatric research, Vol.25(5), pp.461-465
- Publisher
- Lippincott Williams & Wilkins; Hagerstown, MD
- DOI
- 10.1203/00006450-198905000-00007
- PMID
- 2541395
- ISSN
- 0031-3998
- eISSN
- 1530-0447
- Language
- English
- Date published
- 1989
- Academic Unit
- Molecular Physiology and Biophysics; Nephrology, Dialysis and Transplantation; Stead Family Department of Pediatrics; Medicine Administration
- Record Identifier
- 9984025309002771
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