Sequence, circulating levels, and expression of C-type natriuretic peptide in a euryhaline elasmobranch, Carcharhinus leucas.
The present study has examined expression and circulating levels of C-type natriuretic peptide (CNP) in the euryhaline bull shark, Carcharhinus leucas. Complementary DNA and deduced amino acid sequence for CNP in C. leucas were determined by RACE methods. Homology of CNP amino acid sequence in C. leucas was high both for proCNP and for mature CNP when compared with previously identified elasmobranch CNPs. Mature CNP sequence in C. leucas was identical to that in Triakis scyllia and Scyliorhinus canicula. Levels of expression of CNP mRNA were significantly decreased in the atrium but did not change in either the brain or ventricle following acclimation to a SW environment. However, circulating levels of CNP significantly increased from 86.0+/-7.9 fmol ml(-1) in FW to 144.9+/-19.5 fmol ml(-1) in SW. The results presented demonstrate that changes in environmental salinity influences both synthesis of CNP from the heart and also circulating levels in C. leucas. Potential stimulus for release and modes of action are discussed.
Gary Anderson
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University of Manitoba, Department of Zoology, Duff Roblin Building, Winnipeg, Man., Canada. andersow@cc.umanitoba.ca
Hyodo
Susumu
S
Tsukada
Takehiro
T
Meischke
Lara
L
Pillans
Richard D
RD
Good
Jonathan P
JP
Takei
Yoshio
Y
Cramb
Gordon
G
Franklin
Craig E
CE
Hazon
Neil
N
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015870:Gene Expression; D008969:Molecular Sequence Data; D020098:Natriuretic Peptide, C-Type / Q000097:blood / Q000737:chemistry* / Q000378:metabolism*; D012754:Sharks / Q000378:metabolism*; D012965:Sodium Chloride; D014018:Tissue Distribution; D014867:Water
D014867:Water; D020098:Natriuretic Peptide, C-Type; D012965:Sodium Chloride