Lung transplantation in the rat. III. Functional studies in iso- and allografts.

Recently a microsurgical technique for orthotopic left lung transplantation in the rat was developed. The aim of this study was to investigate the influence of the operation itself and of an unmodified rejection reaction on the function of the transplanted rat lung. Orthotopic left lung transplantation was performed in 59 rats (34 isografts and 25 allografts). Isografts demonstrated a mean left lung perfusion of 23.1% in the first two postoperative weeks. Seven out of the 10 animals, subjected to a repeated scintigraphy 5-10 weeks later, had an increased graft perfusion, resulting in an almost normal mean left lung perfusion of 34.8%. At that time chest roentgenography revealed a good aeration of the grafts, that at autopsy had a normal aspect. Allografts showed an initial mean left lung perfusion (24.6%) similar to the isografts, which, however, declined sharply a few days later (4.3%). At that time chest roentgenography revealed totally opalescent grafts that at autopsy had the hepatized aspect characteristic of lung allograft rejection. These results of isogeneic and allogeneic lung transplantation in the rat were comparable with those of canine auto- and allotransplantation. For immunogenetic and economical reasons lung transplantation in the rat is a good alternative animal model in lung transplantation research.