title: The effects of the covalent attachment of 3-(4-hydroxy-3,5-di-tert-butylphenyl) propyl amine to glutaraldehyde pretreated bovine pericardium on structural degeneration, oxidative modification, and calcification of rat subdermal implants.
abstract: Bioprosthetic heart valves (BHV) fabricated from glutaraldehyde pretreated heterograft materials, porcine aortic valves or bovine pericardium (BP), are widely used in cardiac surgery. BHV progressively fail in clinical use due to structural degeneration. Previously we reported that dityrosine, an oxidized amino acid, was present in failed clinical BP-BHV explants; unimplanted BP had no detectable dityrosine. In the same studies BP were demonstrated in vitro to be susceptible to oxidative damage, that could be mitigated with BP covalently modified with the antioxidant, 3-(4-hydroxy-3,5-di-tert-butylphenyl)propyl amine (DBP). The present studies compared in rat subdermal implants glutaraldehyde pretreated BP to BP modified with either DBP or the chemical reactions used to link DBP. All BP explants regardless of DBP demonstrated reduced hydroxyproline and increased digestibility by collagenase. However, the DBP-BP explants showed significant inhibition of reduced explant shrink temperatures (an index of crosslinking) as compared with control BP. Significant mitigation of calcification was observed in both the BP-DBP and chemically modified explants as compared with BP. Dityrosine was not detectable in the 90 day explants. It is concluded that rat subdermal BP implants undergo both calcific and noncalcific structural degeneration, but without the formation of dityrosine, unlike clinical BP explants.
authors.affiliation: Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.|Division of Cardiology, Department of Pediatrics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104.
authors.forename: Abigail J
authors.initials: AJ
authors.lastname: Christian
authors.affiliation: Division of Cardiology, Department of Pediatrics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104.|Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.
authors.forename: Ivan S
authors.initials: IS
authors.lastname: Alferiev
authors.affiliation: Division of Cardiology, Department of Pediatrics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104.
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Connolly
authors.affiliation: Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.|Division of Neonatology, Department of Pediatrics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104.
authors.forename: Harry
authors.initials: H
authors.lastname: Ischiropoulos
authors.affiliation: Department of Pharmacology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.|Division of Cardiology, Department of Pediatrics, the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, 19104.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Levy
mesh_terms: D000818:Animals; D002417:Cattle; D005976:Glutaral / Q000378:metabolism*; D010084:Oxidation-Reduction; D010496:Pericardium / Q000378:metabolism*; D019736:Prostheses and Implants; D051381:Rats
chemical_list: D005976:Glutaral
keywords: antioxidant; bioprosthesis; calcification; heart valve; oxidation