Connective tissue changes and collagen metabolism in syngeneic vena caval grafts in rats

An attempt was made to determine if changes occurring in connective tissue and collagen metabolism of vein-to-artery grafts arose from the trauma of transplantation as such or from the higher pulsatile pressure. Segments of the supradiaphragmatic inferior vena cava were therefore transplanted to the infrarenal vena cava in syngeneic pairs of rats. The sequential changes in hydroxyproline concentration, 3H-proline incorporation and the histologic appearance of collagen, elastic fibres and fibronectin were noted. Comparisons were made with previously reported changes in syngeneic venoartery grafts in rats. The initial changes, probably resulting from the transplantation trauma, were similar in the veno-vein and veno-artery grafts. Subsequent changes, however, were less pronounced in veno-vein than in veno-artery grafts. The study thus suggests that these changes in vein-to-artery grafts are due partly to the transplantation trauma, but mainly to the increased pressure in the new environment.