title: Detection of immunoreactive atrial and brain natriuretic peptides in the equine atrium.
abstract: The distribution of immunoreactivity (IR) for cardiodilatin/atrial natriuretic peptide (CDD/ANP) and brain natriuretic peptide (BNP) was examined immunohistochemically and immuno-electron-microscopically in the equine atrium, using specific antibodies. In the immunohistochemical studies, IR-CDD/ANP and IR-pBNP-26 (porcine BNP-26 immunoreactivity) was detected in the cytoplasm of the auricular cardiocytes, but IR-hBNP-32 (human BNP-32 immunoreactivity) was not. The double immunogold labelling method for IR-hBNP-28 and IR-pBNP-26 revealed that gold particles of different sizes were located in the same secretory granules in the cardiocyte, but no gold particles for IR-hBNP-32 were detected. These results show that CDD/ANP and porcine BNP-like peptides are colocalized in the same secretory granules of the equine atrium. They suggest that the equine atrium secretes both CDD/ANP and BNP-like peptides.
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000032:analysis* / Q000276:immunology; D003429:Cross Reactions; D003594:Cytoplasmic Granules / Q000737:chemistry; D006325:Heart Atria / Q000737:chemistry* / Q000648:ultrastructure; D006736:Horses / Q000378:metabolism*; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D009124:Muscle Proteins / Q000032:analysis* / Q000276:immunology; D020097:Natriuretic Peptide, Brain; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000276:immunology
chemical_list: D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor; C040651:cardiodilatin