Isotransplantation of organ-cultured neonatal pancreas: reversal of alloxan diabetes in the rat.

Pancreases from neonatal rats four to 16 days postpartum were grown in organ culture for from two to nine days. Approximately 10-20 explants, each measuring 1 mm.3 (1 mg.), were grown on a single Millipore filter placed at the gas-liquid interface of a medium consisting of 50 per cent horse serum and 50 per cent chick embryo extract. Following organ culture, an estimated 9-20 mg. of cultured islet tissue were dissociated with collagenase and isotransplanted into the peritoneal cavity of alloxan-diabetic recipients. In seven of eight recipients the diabetes was reversed between 11 and 53 days of posttransplantation. Animals receiving 12-16 mg. of cultured islet attained normoglycemia in 11-20 days; animals receiving 9-10 mg. of cultured islet tissue recovered between 45 and 53 days. These animals have remained symptom-free for over six months. Biopsies of grafts taken from the peritoneal cavity following reversal of diabetes contained well-vascularized islets compared primarily of heavily granulated beta cells. Quantitative analysis of host pancreases by the linear scanning method (biopsied at one to two weeks and four to five months following reversal of the diabetes) demonstrated that the total beta-cell mass was 3 per cent and the total insulin content was 6 per cent of the normal values. Little or no evidence of regeneration of host beta cells was observed. These studies show that a period of organ culture prior to isotransplantation does not impair the ability of islet tissue to reverse alloxan diabetes in the rat.