Comparative study of coronary endothelial dysfunction after heart transplantation in domestic versus microswines

Abstract

The present study was designed to compare the coronary endothelial dysfunction due to rejection and the development of accelerated atherosclerosis after heart transplantation in domestic (Large-White) versus microswines (Yucatan). A porcine model of heterotopic heart transplantation with preoperative immunologic typing of class I and II antigen of the major histocompatibility complex, permitting slow rejection without immunosuppression, was used to study these two end-points. The endothelium-dependent relaxations of allografted epicardial coronary arteries and native coronary arteries from domestic and microswines were compared 60 days after graft implantation using standard organ chamber experiments. There was a significant decrease of relaxations to serotonin and UK 14,304 (agonists coupled to Gi-proteins) and to sodium fluoride, a direct G-protein activator in both allografted coronary arteries from domestic and microswines. There was a significant increase in the prevalence of intimal thickening of allografted coronary arteries in both domestic and microswines. Domestic and microswines are useful animals for the study of coronary endothelial dysfunction and accelerated atherosclerosis after heart transplantation. Potential advantages of the microswines include ease of management for long-term use and chronic studies.