Studies On Calcific Mechanism Of Bioprosthetic Heart Valve And Chemical Modified Effects Of Hydroxyl Chromium

1. Calcific mechanism of bioprosthetic heartvalveBovine pericardium (BP), treated with glutaraldehyde (GA), was treated by nonionic (Triton X-100,Tween 80), anionic ( SDS) and cationic surfactants ( Hexadecyltrimethy ammonium bromide, HTAB). Concentrations of proteoglycans (PG) of the four different surfactant tanned solutions were quantitated by Bitter's mrthod. Some of the treated BP tissues were morphologically checked for PG in ruthenium red stained sections under transmission electron microscope; some of were subdermally implanted in the bake of rabbits(New Zealand female albino rabbites, 8 to 9 weeks of age) for 21 days.Ca²⁺ contents of the BP tissue were quantitatively analyzed. The results indicated that PG contents in Triton X-100, Tween 80 and SDS tanned solutions were three to six times as mnchas that in HTAB. Under electron microscope, PG granules in BP tissues tanned by the former three surfactants were markedly decreased in comparing with that by the latter one, while the Ca²⁺ contents of the former three corresponding implanted BP tissue were only 1/30 of that tanned by HTAB, no marked difference was found between HTAB and control group. It indicates that calcification of bovine pericardial tissue might be related to its PG content.By bowes' method the content of free carboxyl groups in three kinds of different modified BP tissues, which...