Pathologic Calcification and Cell Viability in Rat Allograft Heart Valves

Abstract

Aortic valve allografts are employed in the treatment of patients having aortic valve disease with no apparent rejection or need for immuno-suppression. However, it is unknown whether immunologic differences between donor and recipient affect the performance of the allograft. Because calcification is an important cause of allograft failure, this study was designed to observe the effects of histocompatibility on the degree of allograft calcification.Four groups of ten adult male Lewis rats per group received aortic valve allografts transplanted heterotopically into the abdominal aorta. The aortic valves were obtained from adult male Lewis rats, Brown Norway rats (BN), Fisher rats (F), and Lewis-Brown Norway-Fisher hybrids (LBNF). At 3, 6, 9, and 12 weeks following implantation, the valves were removed, rinsed in saline and washed free of salts using distilled water. They were then mounted to a specimen holder with Tissue-Tek O.C.T. compound and quick frozen in liquid nitrogen. Sections 8um thick, containing leaflet, were cut using a Reichert-Jung cryostat at -20°C and mounted on carbon stubs.