Xenotransplantation—2000

In a rat model, human and rat C peptide have been shown to prevent or attenuate some diabetes induced pathophysiological changes. 9 Porcine C peptide differs considerably from human C peptide and may not have this effect. 8 In contrast, erythropoietin appears to be ineffective in the pig to monkey transplant model but this may be overcome with replacement therapy. 10 These problems will vary depending on which organs are transplanted but are likely to be most marked in the liver owing to the multiple synthetic functions of the organ. Deposition of antibody, predominantly IgM, and terminal complement components can be identified, using immunohistochemical techniques, on the endothelial surface of the graft. 14 The grafts function as though there has been a complete failure in the integrity of the endothelial barrier.\n 46 Much is known about the infectious agents present in domesticated pigs, but new diseases are being recognised. 47 Identified pathogens can be excluded from animals reared as specifically pathogen free. 48, 49 The logistical problems and detrimental effects on growth of rearing pigs in a totally germ-free environment makes this a less attractive option.