Comparative sequences of canine and feline endothelin-1.
BACKGROUND
Endothelin-1 (ET-1, "mature ET-1") is a potent vasoconstrictor peptide that is made along with "big ET-1" from its precursor, preproET-1. Increased plasma concentrations of ET-1 and big ET-1 occur with various forms of cardiovascular disease in humans. Our laboratory is investigating plasma endothelins as diagnostic tests of cardiovascular disease in dogs and cats; however, commercial immunoassays designed specifically for use in dogs and cats are limited.


OBJECTIVE
Amino acid sequences of feline and canine big ET-1 were obtained and used to predict antibody cross-reactivity with immunoassay test kits from other species.


METHODS
Genomic DNA was extracted from peripheral blood and total RNA was extracted from canine and feline left ventricles for reverse transcription polymerase chain reaction (PCR) and PCR amplification of segments of the canine and feline preprohormone containing the big ET-1 sequences. The derived amino acid sequences were compared with known big ET-1 and ET-1 sequences of several other species, including human, mouse, and rat.


RESULTS
Feline and canine big ET-1 had 87-97% and 89-100% homology, respectively, with that of other mammalian species. Canine ET-1 was identical to human, mouse, and rat ET-1. In contrast, the amino acid sequence of feline ET-1 was unique owing to a leucine for methionine substitution at position 7.


CONCLUSIONS
It is highly likely that anti-human and anti-rodent ET-1 antibodies will cross-react with mature canine ET-1. In contrast, antibodies to mature ET-1 intended for use with feline tissues and antibodies to big ET-1 in either dogs or cats may have partial or no cross-reactivity depending on the peptide sequences used to produce the antibodies.
Biondo
Alexander W
AW
Department of Veterinary Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA.
Wiedmeyer
Charles E
CE
Sisson
David D
DD
Solter
Philip F
PF
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D001483:Base Sequence; D002371:Cat Diseases / Q000175:diagnosis; D002415:Cats / Q000235:genetics*; D003429:Cross Reactions; D004283:Dog Diseases / Q000175:diagnosis; D004285:Dogs / Q000235:genetics*; D019332:Endothelin-1 / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D005260:Female; D005784:Gene Amplification; D006331:Heart Diseases / Q000175:diagnosis / Q000662:veterinary*; D007118:Immunoassay / Q000662:veterinary; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D000906:Antibodies; D019332:Endothelin-1; D010446:Peptide Fragments