Al+++ Binding Studies and Metallic Cation Effects on Bioprosthetic Heart Valve Calcification in the Rat Subdermal Model


    loading  Checking for direct PDF access through Ovid

Abstract

Al+++ preincubation has been shown to inhibit calcification of glutaraldehyde pretreated bovine pericardium calcification in the rat subdermal model. This study was designed to assess in vitro the Al+++ (10-1 M, 10-2 M, 10-3 M preincubations) binding characteristics of glutaraldehyde pretreated bovine pericardium. In vivo studies assessed the ability of AlCl3 (10-1 M, 10-2 M, 10-3 M) preincubations to inhibit calcification after 21 and 60 days in the rat subdermal model. Other in vivo studies investigated the ability of other metallic cations (Fe+++, La+++, and Ca+++) used as a pretreatment to inhibit glutaraldehyde pretreated bovine pericardium calcification after a 21 day rat subdermal implant. Lyophylized glutaraldehyde pretreated bovine pericardium samples were analyzed for Al+++ by neutron activation. In vitro results showed the greatest glutaraldehyde pretreated bovine pericardium Al+++ uptake in specimens incubated in 0.1M AlCl3. Maximal Al+++ uptake occurred by 1 hour. Glutaraldehyde pretreated bovine pericardium Al+++ levels after incubation in 10-1 M, 10-2 M, and 10-3 M AlCl3 for 1 hour were 351.4 ± 15.8 nM/mg, 96.4 ± 17.4 nM/mg, and 24.6 ± 4.9 nM/mg, respectively versus 394.5 ± 48.0 nM/mg, 105.3 ± 2.3 nM/mg, 40.0 ± 8.8 nM/mg, respectively for 3 days. In vivo 21 day rat (50–60 g, male, Sprague-Dawley) subdermal implants of 0.1 M AlCl3, FeCl3, FeCl3 plus citrate, LaCl3, and GaNO3 pretreated glutaraldehyde pretreated bovine pericardium showed calcification inhibition by Al+++, Fe+++, and Fe+++ plus citrate (Ca++ = 5.5 ± 0.2 μg/mg, 13.6 ± 4.6 μg/mg, 5.9 ± 1.7 μg/mg, respectively) compared to control (Ca++ = 63.6 ± 5.7 μg/mg). La+++ and Ca+++ did not significantly inhibit glutaraldehyde pretreated bovine pericardium calcification. Sixty day subdermal implants showed glutaraldehyde pretreated bovine pericardium calcification inhibition by glutaraldehyde pretreated bovine pericardium preincubation in 10-1 M and 10-2 M AlCl3 (Ca++ = 5.1 ± 0.9 μg/mg, 11.5 ± 4.6 μg/mg, respectively), but not 10-3 M AlCl3 (Ca++ = 70.3 ± 23.0 μg/mg, control = 110 ± 9.3 μg/mg). No adverse effects on bone or somatic growth were observed in the experimental groups.

    loading  Loading Related Articles