Regional variation of postjunctional α- adrenoceptor responses in the developing renal vascular bed of sheep

ABSTRACT ABSTRACT: Postjunctional α1- and α2-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 (3-5 d age), and nonpregnant adult sheep. Vascular rings were mounted at their optimal resting tension and responses to phenylephrine

(α1-adrenoceptor agonist) and guanabenz and UK 14304 (both α2-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 α1 -adrenoceptor stimulation than to < α2-adrenoceptor stimulation, whereas venous segments

develop similar isometric tension to α1 - and α2-adrenoceptor stimulation. The segmental renal artery develops more isometric tension to α 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 α-adrenoceptor stimulation except for the renal

vein with α 2-adrenoceptor stimulation. Maximum isometric tension corrected for vessel cross-sectional area decreases with age for all vessels with both α1- and α2-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

atand α2-adrenoceptors mediate vasoconstriction in the renal circulation, they may do so at different sites. SIMILAR CONTENT BEING VIEWED BY OTHERS TROPHIC SYMPATHETIC INFLUENCE WEAKENS

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November 2022 ARTICLE PDF AUTHOR INFORMATION Author notes * G Paul Matherne, Beth M Alden & Jean E Robillard Present address: Department of Pediatrics. Division of Pediatric Cardiology,

University of Virginia Medical Center, Box 386, Charlottesville, 22908, VA * Kenneth T Nakamura Present address: Department of Pediatrics. John A. Burns School of Medicine, Kapiolani Medical

Center for Women and Children, Honolulu, 96826, HI * Nancy J Rusch Present address: Department of Physiology. Milwaukee. WI 53226Departments of Pediatrics and the Cardiovascular Research

Center, Medical College of Wisconsin, University of Iowa College of Medicine, Iowa City, 52242, IA AUTHORS AND AFFILIATIONS Authors * G Paul Matherne View author publications You can also

search for this author inPubMed Google Scholar * Kenneth T Nakamura View author publications You can also search for this author inPubMed Google Scholar * Beth M Alden View author

publications You can also search for this author inPubMed Google Scholar * Nancy J Rusch View author publications You can also search for this author inPubMed Google Scholar * Jean E

Robillard View author publications You can also search for this author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Matherne,

G., Nakamura, K., Alden, B. _et al._ Regional Variation of Postjunctional α- Adrenoceptor Responses in the Developing Renal Vascular Bed of Sheep. _Pediatr Res_ 25, 461–465 (1989).

https://doi.org/10.1203/00006450-198905000-00007 Download citation * Received: 10 June 1988 * Accepted: 01 December 1988 * Issue Date: 01 May 1989 * DOI:

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