Document Detail

The calibre of the foramen of Panizza in Crocodylus porosus is variable and under adrenergic control.
MedLine Citation:
PMID:  11409632     Owner:  NLM     Status:  MEDLINE    
The foramen of Panizza is located within the outflow tract of the crocodilian heart, between the left and right aortas. It has been suggested that the foramen of Panizza has a variable calibre, which could explain the profound changes in the distribution of flows and pressure profiles recorded in the right and left aortas. We investigated this possibility using a modified in-situ perfused heart preparation in combination with isolated strip preparations from the outflow tract. In the perfused heart preparation, bolus injections of adrenaline increased the resistance in the foramen of Panizza, indicating a decrease in its diameter. Isolated strip preparations from the outflow tract showed a concentration-dependent increase in tension in response to adrenaline, while vasoactive intestinal polypeptide caused a relaxation in adrenaline pre-contracted strip preparations. We propose that an increase in the diameter of the foramen of Panizza may be important during pulmonary to systemic shunts to allow blood to flow from the left to right aorta (reverse foramen flow) in order to supply the carotid and coronary arteries. During non-shunting conditions, a constricted foramen may prevent excess flow from the right to left aorta during diastole.
M Axelsson; C E Franklin
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology     Volume:  171     ISSN:  0174-1578     ISO Abbreviation:  J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol.     Publication Date:  2001 May 
Date Detail:
Created Date:  2001-06-18     Completed Date:  2001-11-01     Revised Date:  2009-06-08    
Medline Journal Info:
Nlm Unique ID:  8413200     Medline TA:  J Comp Physiol B     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  341-6     Citation Subset:  IM    
Department of Zoology, University of Göteborg, Sweden.
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MeSH Terms
Alligators and Crocodiles / physiology*
Aorta / drug effects,  physiology*
Epinephrine / pharmacology,  physiology*
Vascular Resistance
Vasoactive Intestinal Peptide / pharmacology
Vasoconstriction / drug effects,  physiology*
Vasoconstrictor Agents / pharmacology
Reg. No./Substance:
0/Vasoconstrictor Agents; 37221-79-7/Vasoactive Intestinal Peptide; 51-43-4/Epinephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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