Protein adsorption in glutaraldehyde-preserved bovine pericardium and porcine valve tissues

Background. Proteins adsorbed by bioprosthetic tissues after implantation p lay a major role in the process of calcification. We investigated whether t here are differences in protein adsorption between bovine pericardial and p orcine valvular tissues that could correlate with the differences observed clinically. Methods. Glutaraldehyde-treated bovine pericardial and porcine valve sample s were implanted subcutaneously in rats and retrieved 1 month after implant ation. Total protein content was assessed by Lowry's method. Qualitative an alysis was performed by polyacrylamide gel electrophoresis. Quantitative an alysis was performed by densitometry. Results. Total protein content showed a higher protein concentration in por cine valve tissue than in pericardial tissue: 149 +/- 22.6 mug/mg dry tissu e versus 108 +/- 12.7 mug/mg dry tissue (38% increase). In pericardial tiss ue, four protein bands (17, 16, 15.5, and 13.5 kd) showed decreased concent ration when compared with porcine valve tissue, whereas one band (11 kd) sh owed increased concentration. Conclusions. Significant differences were found in protein content between bovine pericardial and porcine valve tissues. Correlations with clinical fi ndings may lead to a better understanding of the mechanism involved in the process of calcification, particularly the role played by the structure of the tissues. (C) 2001 by The Society of Thoracic Surgeons.