Hormone-dependent dissociation of blood flow and secretion rate in the lingual salt glands of the estuarine crocodile, Crocodylus porosus

Cramp, Rebecca L., De Vries, Inga, Anderson, W. Gary and Franklin, Craig E. (2010) Hormone-dependent dissociation of blood flow and secretion rate in the lingual salt glands of the estuarine crocodile, Crocodylus porosus. Journal of Comparative Physiology B. Biochemical, Systematic and Environmental Physiology, 180 6: 825-834. doi:10.1007/s00360-010-0464-z


Author Cramp, Rebecca L.
De Vries, Inga
Anderson, W. Gary
Franklin, Craig E.
Title Hormone-dependent dissociation of blood flow and secretion rate in the lingual salt glands of the estuarine crocodile, Crocodylus porosus
Formatted title
Hormone-dependent dissociation of blood flow and secretion rate in the lingual salt glands of the estuarine crocodile, Crocodylus porosus
Journal name Journal of Comparative Physiology B. Biochemical, Systematic and Environmental Physiology   Check publisher's open access policy
ISSN 0174-1578
Publication date 2010-08
Sub-type Article (original research)
DOI 10.1007/s00360-010-0464-z
Volume 180
Issue 6
Start page 825
End page 834
Total pages 10
Editor Gerhard Heldmaier
Place of publication Berlin, Germany ; New York, U.S.A.
Publisher Springer International
Collection year 2011
Language eng
Subject C1
Formatted abstract
Salt and water balance in the estuarine crocodile, Crocodylus porosus, involves the coordinated action of both renal and extra-renal tissues. The highly vascularised, lingual salt glands of C. porosus excrete a concentrated sodium chloride solution. In the present study, we examined the in vivo actions of vasoactive intestinal peptide (VIP), B-type natriuretic peptide (BNP) and angiotensin II (ANG II) on the secretion rate and blood perfusion of the lingual salt glands. These peptides were selected for their vasoactive properties in addition to their reported actions on salt gland activity in birds and turtles and rectal gland activity in elasmobranchs. The femoral artery was cannulated in seven juvenile crocodiles for delivery of peptides and measurement of mean blood pressure and heart rate. In addition, secretion rate of, and blood flow to, the salt glands were recorded simultaneously using laser Doppler flowmetry. VIP stimulated salt secretion was coupled to an increase in blood flow and vascular conductance of the lingual salt glands. BNP was a potent stimulant of salt gland secretion, resulting in a maximal secretion rate of more than 15-fold higher than baseline; however, this was not coupled to an increase in perfusion rate, which remained unchanged. ANG II failed to stimulate salt gland secretion and there was a transient decrease in salt gland blood flow and vascular conductance. It is evident from this study that blood flow to, and secretion rate from, the lingual salt glands of C. porosus are regulated independently; indeed, it is apparent that maximal secretion from the salt glands may not require maximal blood flow.
© 2010 Springer-Verlag.
Keyword Crocodilian
Osmoregulation
Salt gland
Secretion rate and blood flow
Atrial-natriuretic-peptide
Elasmobranch rectal gland
Duck anas-platyrhynchos
Ii-induced attenuation
Conscious pekin ducks
Squalus-acanthias
Angiotensin-I
Functional evolution
Chloride secretion
Vasoactive intestinal polypeptide
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2011 Collection
School of Biological Sciences Publications
 
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Created: Sun, 08 Aug 2010, 00:03:57 EST