The present invention is to provide a novel peptide having a potent hypotensive activity by inhibiting cardiac contractility, a DNA encoding the peptide, an antibody against the peptide, or a cardioinhibitory/hypotensive agent comprising the peptide as an active ingredient. A search of a genetic data base revealed the presence of a peptide biosynthesized by a processing of unspliced product of TOR2A mRNA. As a result of functional analysis, a peptide hormone exerting a potent bioactivity and expressed abundantly throughout human organs was found. The peptide is hydrophobic with a molecular weight of 2664.02 consisting of 24 amino acids (AIFIFISNTGGKQINQVALEAWRS; SEQ ID NO.: 2) and shows a negative inotropism in rat hearts, as well as a marked systemic hypotensive activity.