AJP - Heart AJP: Cell Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 263: H1605-H1615, 1992;
0363-6135/92 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hanley, D. F.
Right arrow Articles by Brayden, J. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hanley, D. F.
Right arrow Articles by Brayden, J. E.

AJP - Heart and Circulatory Physiology, Vol 263, Issue 5 1605-H1615, Copyright © 1992 by American Physiological Society

ARTICLES

Neural mechanisms regulating neurohypophysial resistance arteries

D. F. Hanley, D. A. Wilson, M. A. Conway, R. J. Traystman, J. A. Bevan and J. E. Brayden
Department of Anesthesiology/Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.

We defined the extent of vasoactive intestinal polypeptide (VIP) and noradrenergic influences on isolated 100- to 200-microns-diameter vessels from the resistance arterial circulation of the neurohypophysis. A dual extracranial (inferior hypophysial) and intracranial (superior hypophysial) arterial supply to the neurohypophysis was confirmed. The inferior hypophysial artery demonstrates noradrenergic and VIP-like perivascular nerves, whereas the superior hypophysial artery shows primarily VIP-like innervation. Pharmacological sensitivity of the inferior hypophysial to VIP [mean effective dose (ED50) = 10(-8.2) M] and to norepinephrine (ED50 = 10(-5.7) M) was demonstrated. The superior hypophysial reacted only to VIP (ED50 = 10(-8.6) M). The physiological relevance of these findings was tested with transmural nerve stimulation. Frequency-dependent vasodilation of both inferior and superior hypophysial arteries was demonstrated. This dilation could not be blocked with atropine or propranolol. Frequency-dependent vasoconstriction was identified in extracranial vessels including the inferior hypophysial artery. This constriction is only partially blocked by prazosin, phentolamine, and guanethidine. When neurohypophysial resistance vessels are compared with larger circle of Willis arteries and similar-size pial vessels of other cerebral regions, they appear to have regionally unique neural mechanisms for regulating blood flow. Specifically whether controlled by periarterial nerves or other tissue influences, the inferior hypophysial artery appears to meet anatomic, pharmacological, and physiological definitions of neural control for both dilator and constrictor activities of flow to the neurohypophysis.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
B. P. Wagner, R. Stingele, M. A. Williams, D. A. Wilson, R. J. Traystman, and D. F. Hanley
NO contributes to neurohypophysial but not other regional cerebral fluorocarbon-induced hyperemia in cats
Am J Physiol Heart Circ Physiol, October 1, 1997; 273(4): H1994 - H2000.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online