Pronatriuretic peptide is a sensitive marker of the endocrine function of teleost heart.
We recently characterized a novel heart-specific hormone from salmon (salmon cardiac peptide, sCP). We have now prepared a recombinant plasmid expressing the NH(2)-terminal fragment of pro-sCP (NT-pro-sCP) and used it to set up a specific RIA for the peptide. Because of the sensitivity of the assay and the high circulating levels, NT-pro-sCP can be measured from as little as 2 microl of serum. This enables repeated sampling from the same animal in different experimental setups. Mechanical load increased the release of NT-pro-sCP from isolated perfused salmon ventricle, in parallel with sCP. Bolus injection of human endothelin-1 (ET-1; 1 microg) in the dorsal aorta of salmon resulted in an extensive increase of serum NT-pro-sCP (from 0.99 +/- 0.11 to 4.6 +/-1.5 nmol/l). The response was abolished by pretreatment with a specific type A ET (ET(A)) receptor antagonist (BQ-123) but not with a type B ET receptor antagonist (BQ-788). The NT-pro-sCP levels had a good correlation with those of sCP (r(2) = 0.75). Our results demonstrate the practical usefulness of circulating NT-pro-sCP as a marker of the endocrine function of salmon heart. They also suggest that ET-1 has an important role in regulating sCP release from teleost heart by an ET(A) receptor-mediated mechanism.
Vierimaa
Heidi
H
Department of Physiology, Biocenter Oulu, University of Oulu, Finland.
Hirvinen
Minna
M
Tervonen
Virpi
V
Arjamaa
Olli
O
Ruskoaho
Heikki
H
Vuolteenaho
Olli
O
D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000187:drug effects; D015415:Biomarkers / Q000097:blood*; D002352:Carrier Proteins / Q000097:blood* / Q000235:genetics; D002851:Chromatography, High Pressure Liquid; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology; D029941:Fish Proteins; D005982:Glutathione Transferase / Q000235:genetics; D006321:Heart / Q000502:physiology*; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D045265:Natriuretic Peptides; D010446:Peptide Fragments / Q000097:blood*; D010456:Peptides, Cyclic / Q000494:pharmacology; D011498:Protein Precursors / Q000097:blood*; D011863:Radioimmunoassay; D044022:Receptor, Endothelin A; D011993:Recombinant Fusion Proteins; D012474:Salmon / Q000502:physiology*; D014157:Transcription Factors / Q000097:blood* / Q000235:genetics
D015415:Biomarkers; D002352:Carrier Proteins; D065128:Endothelin Receptor Antagonists; D019332:Endothelin-1; D029941:Fish Proteins; D045265:Natriuretic Peptides; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D011498:Protein Precursors; D044022:Receptor, Endothelin A; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C403482:cardiac natriuretic peptide, Salmo salar; D005982:Glutathione Transferase; C072247:cyclo(Trp-Asp-Pro-Val-Leu)