title: Prophylactic effects of elastin peptide derived from the bulbus arteriosus of fish on vascular dysfunction in spontaneously hypertensive rats.
abstract: OBJECTIVE
  To determine the prophylactic effects of an elastin peptide derived from the bulbus arteriosus of bonitos and prolylglycine (PG), a degradation product of elastin peptide, on vascular dysfunction in spontaneously hypertensive rats (SHRs).
  
  
  METHODS
  Male 15-week-old SHR/Izm rats were fed without (control group) or with elastin peptide (1 g/kg body weight) for 5 weeks (EP group), or were infused via an osmotic mini-pump for 4 weeks with PG (PG group) or saline (control group). Using thoracic aortas, we assessed endothelial changes by scanning electron microscopy. Vascular reactivity (contraction and relaxation) and pressure-induced distension was compared. mRNA production levels of endothelial nitric oxide synthase (eNOS) and intercellular adhesion molecule-1 (ICAM-1) were investigated by real-time-polymerase chain reaction.
  
  
  RESULTS
  Aortas of the EP group displayed limited endothelial damage compared with that in the control group. Under treatment of SHRs with elastin peptide, the effect of phenylephrine returned closer to the normal level observed in normotensive Wistar-Kyoto (WKY/Izm) rats. mRNA production of eNOS (but not ICAM-1) was greater in the EP group than in the control group. Endothelial damage was suppressed and pressure-induced vascular distension was greater in the PG group than in the corresponding control group.
  
  
  CONCLUSIONS
  These results suggest that elastin peptide from bonitos elicits prophylactic affects hypertension-associated vascular dysfunction by targeting the eNOS signaling pathway. PG may be a key mediator of the beneficial effects of elastin peptide.
authors.affiliation: Department of Food and Nutrition, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan. Electronic address: kuriman@nara.kindai.ac.jp.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Takemori
authors.affiliation: Department of Medical Engineering, Faculty of Biology-Oriented Science and Technology, Kinki University, 930 Nishimitani, Kinokawa, Wakayama 649-6493, Japan.
authors.forename: Ei
authors.initials: E
authors.lastname: Yamamoto
authors.affiliation: Department of Medical Engineering, Faculty of Biology-Oriented Science and Technology, Kinki University, 930 Nishimitani, Kinokawa, Wakayama 649-6493, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ito
authors.affiliation: Department of Food and Nutrition, Faculty of Agriculture, Kinki University, 3327-204 Nakamachi, Nara 631-8505, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kometani
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology*; D001696:Biomechanical Phenomena; D001794:Blood Pressure / Q000187:drug effects; D004151:Dipeptides / Q000737:chemistry*; D004549:Elastin / Q000737:chemistry*; D004727:Endothelium / Q000187:drug effects* / Q000648:ultrastructure; D005399:Fishes; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D060888:Real-Time Polymerase Chain Reaction; D014652:Vascular Diseases / Q000188:drug therapy*
chemical_list: D004151:Dipeptides; D018799:Intercellular Adhesion Molecule-1; C057749:prolylglycine; D004549:Elastin; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat
keywords: Elastin peptide; Endothelium; Spontaneously hypertensive rats; Vascular tone