A1 +++ Pretreatment Inhibits Calcification of Aortic Homografts Implanted Subcutaneously in rats
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Authors
Phelps, Lisa L.
Issue Date
1988
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Valved aortic homografts are often used to replace
diseased cardiac valves. Calcification of these homograft
valves may lead to clinical failure requiring reoperation.
Preventing such calcification, therefore, presents an
important challenge. The trivalent cation aluminum (Al+++)
effectively inhibits calcification in bioprosthetic heart
valve leaflets fabricated from glutaraldehyde pretreated
porcine aorta or bovine pericardium subcutaneously implanted
in rats, without adverse side effects. The objectives of
this study were 1) to characterize calcification of aortic
homografts in the rat subcutaneous model and 2) to assess the
ability of Al+++ to inhibit homograft calcification. Thoracic
aortas from 200-300 g Rattus norvegicus (male, CD, Sprague
Dawley) were removed, washed, and incubated in AlCl3
solutions (0.01 M, 0.001 M, 0.0001 M) for one hour at 4 °C.
The homografts were implanted subcutaneously in weanling rats
(50-60 g) of the same species for 21 d. Control aortas were
similarly removed from 200-300 g rats and implanted without
pretreatment. The control aortic implants were retrieved
periodically at 1,2,3,7, and 21 d. The explanted homografts
were analyzed for calcium and aluminum content. The results
showed that 1) aortic homografts not pretreated with Al+++
calcified severely at Ca++ levels comparable to those observed
in bioprosthetic heart valve leaflets, 2) homograft
preincubation in 0.01 M and 0.001 M AlCl3 significantly
(p<0.05) inhibited calcification, and 3) no adverse side
effects on somatic or bone growth occurred in rats implanted
with AI+++ treated aortas. It is concluded that the rat
subcutaneous model provides an effective method for studying
characteristics of aortic homograft calcification and that
aluminum (Al+++) can effectively inhibit homograft
calcification without adverse effects.
Description
vi, 30 p.
Citation
Publisher
Kalamazoo College
License
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