Slow and incomplete sympathetic reinnervation of rat tail artery restores the amplitude of nerve-evoked contractions provided a perivascular plexus is present

Tripovic, Diana, Pianova, Svetlana, McLachlan, Elspeth M. and Brock, James A. (2011) Slow and incomplete sympathetic reinnervation of rat tail artery restores the amplitude of nerve-evoked contractions provided a perivascular plexus is present. American Journal of Physiology-heart And Circulatory Physiology, 300 2: H541-H554. doi:10.1152/ajpheart.00834.2010


Author Tripovic, Diana
Pianova, Svetlana
McLachlan, Elspeth M.
Brock, James A.
Title Slow and incomplete sympathetic reinnervation of rat tail artery restores the amplitude of nerve-evoked contractions provided a perivascular plexus is present
Journal name American Journal of Physiology-heart And Circulatory Physiology   Check publisher's open access policy
ISSN 0363-6135
1522-1539
Publication date 2011-02-01
Year available 2010
Sub-type Article (original research)
DOI 10.1152/ajpheart.00834.2010
Volume 300
Issue 2
Start page H541
End page H554
Total pages 14
Place of publication Bethesda MD, United States
Publisher American Physiological Society
Language eng
Formatted abstract
We have investigated the recovery of sympathetic control following reinnervation of denervated rat tail arteries by relating the reappearance of noradrenergic terminals to the amplitude of nerve-evoked contractions of isometrically mounted artery segments in vitro. We have also assessed reactivity to vasoconstrictor agonists. Freezing the collector nerves near the base of the tail in adult rats denervated the artery from ~40 mm along the tail. Restoration of the perivascular plexus declined along the length of the tail, remaining incomplete for >6 mo. After 4 mo, nerve-evoked contractions were prolonged but of comparable amplitude to control at ~60 mm along the tail; they were smaller at ~110 mm. At ~60 mm, facilitation of contractions to short trains of stimuli by the norepinephrine transporter blocker, desmethylimipramine, and by the α2-adrenoceptor antagonist, idazoxan, was reduced in reinnervated arteries. Blockade of nerve-evoked contractions by the α1-adrenoceptor antagonist, prazosin, was less and by idazoxan greater than control after 8 wk but similar to control after 16 wk. Sensitivity of reinnervated arteries to the α1-adrenoceptor agonist, phenylephrine, was raised in the absence but not in the presence of desmethylimipramine. Sensitivity to the α2-adrenoceptor agonist, clonidine, was maintained in 16-wk reinnervated arteries when it had declined in controls. Thus regenerating sympathetic axons have a limited capacity to reinnervate the rat tail artery, but nerve-evoked contractions match control once a relatively sparse perivascular plexus is reestablished. Functional recovery involves prolongation of contractions and deficits in both clearance of released norepinephrine and autoinhibition of norepinephrine release.
Keyword Sympathetic nerves
Nerve injury
Vascular reactivity
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online before print November 2010

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
School of Biomedical Sciences Publications
 
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Created: Sun, 20 Mar 2011, 10:12:53 EST