Effect of low-temperature culture and L3T4 antibody on the survival of pancreatic islets xenograft (fish to mouse).

Catfish (Ictalurus punctatus) islets were transplanted into the renal subcapsular space of diabetic C57BL/6J mice. The xenograft mean survival time (MST) of islets cultured for 6 days at 24 degrees C was 4.9 +/- 0.5 days, while xenotransplantation of 1-hour-cultured islets did not restore normoglycemia in the diabetic mice. A modest but significant prolongation of the MST was obtained by administration of anti-L3T4 monoclonal antibody to the recipients (13.4 +/- 2.1 days). Anti-L3T4 in conjunction with low-temperature culture did not produce a further increase of the MST (9.1 +/- 2.7 days). These findings indicate that catfish islets may be a source of islet tissue for transplantation in diabetic recipients. However, procedures that demonstrated to be effective in prolonging the MST of xenografts transplanted across wide species barrier, such as low-temperature culture and anti-L3T4 treatment, failed to prolong markedly the xenograft survival. Further experimental work is needed to study the possibility of improving islets survival after xenotransplantation across distant species barrier (fish to mouse).