Novel Fish-derived Peptides Which Induce Vasorelaxation of Porcine Coronary Arteries

Abstract

Vasodilators are widely and frequently used for the acute or chronic phases of cardiovascular diseases, including ischemic heart diseases, hypertension, and heart failure. To enable the reliable prevention of such cardiovascular diseases, we attempted to discover foods or food components that induce vasorelaxation of the porcine coronary arteries. In the present study, after extensive screening, we eventually identified fish-derived peptide fragments（FDPFs），which were obtained via the edible enzyme digestion of fish proteins.

Using tandem mass spectrometry, we identified four novel peptides with sequential amino-acid sequence（VGPGG, VGPG, GPG and PG）among the FDPFs. These peptides are previously unreported and induced concentration-dependently strong and sustained vasorelaxation. The extents of the relaxation increased as the length of the peptides are longer, suggesting the involvement of the membrane receptor. The most potent and longest peptide, VGPGG induced vasorelaxation without any changes in［Ca２+］i, indicating the decrease in Ca２+-sensitivity of smooth muscle contraction. These findings support the possibility that these FDPFs may be highly promising food components for use in the prevention of cardiovascular diseases. In addition, these novel peptide are also highly soluble in water and therefore might have applications as intravenously injectable medication for the treatment of acute and severe cardiovascular diseases.